Reoccurring problems every grow WOODY J (UK) to the rescue

[fartoblue]

OK. After reading the whole thread, and looking close....

I have several issues you should address.

Nizza is correct! Control the res or buckets to under 70 but not below 65 F.

pH... STOP allowing that pH to drop to 55 - AS BEST YOU CAN... This is better controlled by setting the pH to 6.2 or 6.3 in the mourning.
I know many who like low pH in hydro BUT, it is easy for it to lead to issues...just like yours. ESPECIALLY SINCE THE pH SHOULD BE A CPL OF TENTHS HIGHER IN BLOOM! Your way to low for blooming cannabis in hydro.
Rule of thumb in hydro applications for pH values... 5.7 to 6.3 The common quality book scale is 5.8 to 6.2.....
Part of the above issue is likely a habit of not dumping and starting with fresh nutrient mix properly. The other side of that coin is how much in concentration your adding back to "top off" the tank or buckets...

Waste build-up from the plant effects the ability of the mix in the bucket to work properly..

Lets take a look at a simple solution to that. "The 33% add back rule"
This is an old school, original hydro rule that still works well today!

Fill your res/bucket with your 100% feed solution. Note how much in volume you filled it with.
Now as that res/bucket reduces in solution, you add back to top off,,,correct? Keeping track of how much your adding back..

You should be adding back a 33% concentration of that feed solution and not 100%...

To make a 33% solution: Simply take a gallon of the 100% solution and add two (2) more gallons of plain water to it. You now have a 33% solution.

Top off using that 33% solution.
Now here's the other important part. Remember I asked you to keep track of how much your adding back?
Now when the amount you would add back comes to equal the amount you filled the res/bucket with the first time.
DUMP AND REFILL WITH 100% SOLUTION and restart the whole topping off with 33% all over again.

Do this in veg AND bloom!

Lastly: Mixing
Add each chemical after adding an amount of water.
EXAMPLE: Your making 3 gallons of 100% mix.
Add 4 cups of water to your mixing container.
Add the first chem by pouring the next 4 cup scoop over the measuring cup with the chem in it.
Rinse the measuring cup (I use a 60ml mini cup)
Now do the same for the each chemical you add. ALWAYS ADD THE CAL/MAG LAST.
Now pH your solution and use it.

I get the distinct feeling your not dumping and refilling enough and are suffering from hydro waste build-up..

This sure won't hurt you, so give it a big try out.

Good luck!

Many thanks for taking the time to read this thread and giving such a detailed and informative response, it is really appreciated and apologies for taking so long to get back.
I will be putting some new plants into this system in a week or so and will implement everything you have suggested.

Nizza is correct! Control the res or buckets to under 70 but not below 65 F. This may have been a problem as I did take the aquarium heaters out and the res temps went as low as 55 F during lights off.

pH... STOP allowing that pH to drop to 55 - AS BEST YOU CAN... This is better controlled by setting the pH to 6.2 or 6.3 in the mourning.
I know many who like low pH in hydro BUT, it is easy for it to lead to issues...just like yours. ESPECIALLY SINCE THE pH SHOULD BE A CPL OF TENTHS HIGHER IN BLOOM! Your way to low for blooming cannabis in hydro.
Rule of thumb in hydro applications for pH values... 5.7 to 6.3 The common quality book scale is 5.8 to 6.2.....
Part of the above issue is likely a habit of not dumping and starting with fresh nutrient mix properly. The other side of that coin is how much in concentration your adding back to "top off" the tank or buckets... I do think PH fluctuations have been a big problem especially low PH and obvious (classic) signs of calcium deficiency. PH has always dropped and has been below 6 for most of the time. I did PH up to 6 most mornings but it would drop rappidly to as low as 5.4 overnight. I have had rot in the system but not this time (at least not in the roots but there may still have been pathogens lurking in the system)

Waste build-up from the plant effects the ability of the mix in the bucket to work properly.. I have been thinking about this and it could be the problem. The system recirculates but the inlet outlet for each tub is around 3 " from the bottom and the nutrient level 5" above.
I may put an elbow on the outlet from the tub so it pulls from lower down and increase the recirculating pump size to give it a bit more movement. Could some nutrients be heavier and sit in the bottom of the tubs unused??
I will also put a mesh filter on the outlet that runs into the epicenter. Maybe also flush more tap water through the buckets to mix with the residue in the bottom of the buckets and then drain again, realistically I have only been doing partial change outs maybe just over half.

Lets take a look at a simple solution to that. "The 33% add back rule"
This is an old school, original hydro rule that still works well today! This could also be a big problem I have been adding back at full strength or more although I do feed quite low 1.3ec - 1.4 full bloom with a 0.2 background, 3 feeds per day. I generally add back plain water for the last few weeks before harvest and amazingly the PH becomes stable. My most dramatic PH swings are at around 2-5 weeks into 12/12. This is also when the calcium deficiency shows up followed by dry crispy dead leaves all over the tops.

Fill your res/bucket with your 100% feed solution. Note how much in volume you filled it with.
Now as that res/bucket reduces in solution, you add back to top off,,,correct? Keeping track of how much your adding back..

You should be adding back a 33% concentration of that feed solution and not 100%...

To make a 33% solution: Simply take a gallon of the 100% solution and add two (2) more gallons of plain water to it. You now have a 33% solution.

Top off using that 33% solution.
Now here's the other important part. Remember I asked you to keep track of how much your adding back?
Now when the amount you would add back comes to equal the amount you filled the res/bucket with the first time.
DUMP AND REFILL WITH 100% SOLUTION and restart the whole topping off with 33% all over again. This really does make sense and it is something I have never heard of before. My plants seem to drink quite a lot then almost stop.. It is as if they are not transpiring and drying up yet my humidity (40 - 50) and temps (18 night - 24 lights on) are perfect with lots of air flow.

Do this in veg AND bloom!

Lastly: Mixing
Add each chemical after adding an amount of water.
EXAMPLE: Your making 3 gallons of 100% mix.
Add 4 cups of water to your mixing container.
Add the first chem by pouring the next 4 cup scoop over the measuring cup with the chem in it.
Rinse the measuring cup (I use a 60ml mini cup)
Now do the same for the each chemical you add. ALWAYS ADD THE CAL/MAG LAST.
Now pH your solution and use it. Most times I do it like this apart from I add the Botanicare cal/mag first to get my water to 0.5ec. Occasionally I add directly to the epicenter.

I get the distinct feeling your not dumping and refilling enough and are suffering from hydro waste build-up.. I do think you may be correct as everything seems to start off so well (12/12) and then go downhill.

This sure won't hurt you, so give it a big try out. I most certainly will, and will update with the results.

Good luck! And good luck to you my friend, many thanks.

 

[Dr. Who]

Waste build-up from the plant effects the ability of the mix in the bucket to work properly.. I have been thinking about this and it could be the problem. The system recirculates but the inlet outlet for each tub is around 3 " from the bottom and the nutrient level 5" above.
I may put an elbow on the outlet from the tub so it pulls from lower down and increase the recirculating pump size to give it a bit more movement. Could some nutrients be heavier and sit in the bottom of the tubs unused??
I will also put a mesh filter on the outlet that runs into the epicenter. Maybe also flush more tap water through the buckets to mix with the residue in the bottom of the buckets and then drain again, realistically I have only been doing partial change outs maybe just over half.

Heavy Nutes? No. They will remain well mixed in any situation with recirculation or simple res buckets with an air stone.
Always dump and refill completely in hydro applications with any res system.

Lets take a look at a simple solution to that. "The 33% add back rule"
This is an old school, original hydro rule that still works well today! This could also be a big problem I have been adding back at full strength or more although I do feed quite low 1.3ec - 1.4 full bloom with a 0.2 background, 3 feeds per day. I generally add back plain water for the last few weeks before harvest and amazingly the PH becomes stable. My most dramatic PH swings are at around 2-5 weeks into 12/12. This is also when the calcium deficiency shows up followed by dry crispy dead leaves all over the tops.

This says to me that is a large part of the problem.
Combine that with the pH issue (They play off each other - BIG time) and you have your problems in a nut shell.

Top off using that 33% solution.
Now here's the other important part. Remember I asked you to keep track of how much your adding back?
Now when the amount you would add back comes to equal the amount you filled the res/bucket with the first time.
DUMP AND REFILL WITH 100% SOLUTION and restart the whole topping off with 33% all over again. This really does make sense and it is something I have never heard of before. My plants seem to drink quite a lot then almost stop.. It is as if they are not transpiring and drying up yet my humidity (40 - 50) and temps (18 night - 24 lights on) are perfect with lots of air flow.

That is exactly the plant waste build up in the res system doing what you describe.

As to the rest. Yup, this will fix you up, straight away.

This is so old school on hydro use "rules", yet back in the day when it was very new. This method (33% add back rule) cured so many ill's at one time, I'm kinda of shocked it still isn't being taught in books..
Dumping and refilling is how you get to the "next level" of hydro quality. You will be very happy with the yield increase you will get from where your at know...

Drop me a line sometime and we can discuss how to manipulate terps and trich's. Increase THC or CBD levels.
This is a bit more advanced chemical wise. It will also require strict time schedule's for use.

The following works very well, and should be part of your next run too!
You might change your Cal/Mag to a calcium carbonate based cal source (G&H CALi MAGic). This will provide the extra Mag you need and the cal will be more pH stabilizing, and yet be available enough to the plant.

At 61 and have put my first seed to soil at 15... Being in the industry..... I come here for just these types of things. To share and help!

Glad I could!

Peace On....

 

[sandman83]

hmmm I've just been using the fill back method with nutes depending on PPM. Might be worth pumping out the tank and refilling next week it looks like.


I'm a tad confused on the cal/mag timing still though, I typically add silica first, wait an hour, then cal-mag, wait, then the rest of base nutes in order etc. According to yours I should be doing cal-mag after the base nutes?

 

[myke]

hmmm I've just been using the fill back method with nutes depending on PPM. Might be worth pumping out the tank and refilling next week it looks like.


I'm a tad confused on the cal/mag timing still though, I typically add silica first, wait an hour, then cal-mag, wait, then the rest of base nutes in order etc. According to yours I should be doing cal-mag after the base nutes?

I do the same,silica,CaMg ,nutes,ph.My fill back has always just been straight water.

 

[Dr. Who]

I do the same,silica,CaMg ,nutes,ph.My fill back has always just been straight water.

hmmm I've just been using the fill back method with nutes depending on PPM. Might be worth pumping out the tank and refilling next week it looks like.


I'm a tad confused on the cal/mag timing still though, I typically add silica first, wait an hour, then cal-mag, wait, then the rest of base nutes in order etc. According to yours I should be doing cal-mag after the base nutes?

The whole idea of separation with Silica and cal/mag is that you must add them as far apart, and mix well between them. They react by creating a precipitate (cloudy looking solution)

The idea of one first and the other last is the point.....

 

[sandman83]

The whole idea of separation with Silica and cal/mag is that you must add them as far apart, and mix well between them. They react by creating a precipitate (cloudy looking solution)

The idea of one first and the other last is the point.....

I have definitely seen that cloudy solution, ever since I started giving the silica an hour to dissolve in the water before adding the rest I haven't seen it again. I use a graduated cylinder to measure nutes and when I added calmag it made that nasty cloudy stuff all over one of em. I rinse em really well now between but have an extra just for silica.

 

[Dr. Who]

I have definitely seen that cloudy solution, ever since I started giving the silica an hour to dissolve in the water before adding the rest I haven't seen it again. I use a graduated cylinder to measure nutes and when I added calmag it made that nasty cloudy stuff all over one of em. I rinse em really well now between but have an extra just for silica.

Do one first and the other last......Mix well with each chemical added in-between. You should loose your issue.

 

[sandman83]

Do one first and the other last......Mix well with each chemical added in-between. You should loose your issue.

its gone away already, solved the issue. but yeah I'll keep that in mind and probably toss cal-mag in at the end from now on. good looking out!

 

[myke]

The whole idea of separation with Silica and cal/mag is that you must add them as far apart, and mix well between them. They react by creating a precipitate (cloudy looking solution)

The idea of one first and the other last is the point.....

Well that exsplains the cloudy brown water,was really hard to see in a black rez .Wasn't until I filled my glass to check ph that I noticed.Thanks.

 

[fartoblue]

Heavy Nutes? No. They will remain well mixed in any situation with recirculation or simple res buckets with an air stone.
Always dump and refill completely in hydro applications with any res system.



This says to me that is a large part of the problem.
Combine that with the pH issue (They play off each other - BIG time) and you have your problems in a nut shell.



That is exactly the plant waste build up in the res system doing what you describe.

As to the rest. Yup, this will fix you up, straight away.

This is so old school on hydro use "rules", yet back in the day when it was very new. This method (33% add back rule) cured so many ill's at one time, I'm kinda of shocked it still isn't being taught in books..
Dumping and refilling is how you get to the "next level" of hydro quality. You will be very happy with the yield increase you will get from where your at know...

Drop me a line sometime and we can discuss how to manipulate terps and trich's. Increase THC or CBD levels.
This is a bit more advanced chemical wise. It will also require strict time schedule's for use.

The following works very well, and should be part of your next run too!
You might change your Cal/Mag to a calcium carbonate based cal source (G&H CALi MAGic). This will provide the extra Mag you need and the cal will be more pH stabilizing, and yet be available enough to the plant.

At 61 and have put my first seed to soil at 15... Being in the industry..... I come here for just these types of things. To share and help!

Glad I could!

Peace On....

Thanks again Dr

I am also coming up 61 (in May) but only planted my first seed 3 years ago so have a lot of catching up to do.

Unfortunately we can't get Calimagic in the UK or any other water soluble Calcium Carbonate for Hydro. I did notice some contain calcium oxide rather than nitrate..

I will take you up on your kind offer to discus more advanced techniques as soon as I get my system dialed in, probably do your head in as I overthink everything, life in general as well as growing weed! I have some Bodhi SSDD seeds in the fridge so may pick your brains when I set them away and hopefully get a keeper mother.

Blue

 

[Kassiopeija]

Hello, this is an interesting subject to talk about and maybe I can help to clear a few things up or maybe someone could teach me lesson, still need to learn alot about plant physiology, hope I don't forget all of it because of lol

First of all, this theory

Woody's advice below

Most people assume that with a rising EC, it is the plants way of saying, I don't want more food, here, have some back.

What is actually happening is this.

Plants roots take in water/nutrients through a process called Osmosis. Effectively, if you think in terms of the roots having their own internal EC.
The osmosis process will always try to balance out the EC's, taking from the higher side of the barrier and giving to the lower part.

So if the EC of the nutrient solution is higher than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process.
"If however, the EC of the solution is lower than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution. "
A res change or increase in EC should resolve depending on the other factors such as ph and water levels.

contradicts this

Thanks for this Merlin. I read this (below) on another site an this is what made me think about the equalization thing.

Another concept, osmosis, is the net movement of water driven by solute concentrations across a membrane that is semi-permeable and selective. If the solute concentration is higher on one side of the membrane, water will move to create an equilibrium between intracellular (inside a cell) and extracellular (outside the cell) solute concentrations. This movement of water creates a pressure either inward or outward. For example, think of a balloon filled with solute (NaCl). Next, imagine that balloon is surrounded by pure water. Since the concentration of salt inside the balloon is high, water will move into the balloon and place pressure that will inflate the balloon. Without outward rectification, the balloon would pop; thus, salts must be transferred out to reduce this water (osmotic) pressure.

I've highlighted the respective parts.

The second example is actually in line with how wikipedia describes osmosis in plants/cells/biology:
"Osmosis is the movement of a solvent across a semipermeable membrane toward a higher concentration of solute (lower concentration of solvent). In biological systems, the solvent is typically water, but osmosis can occur in other liquids, supercritical liquids, and even gases.[11][12]

When a cell is submerged in water, the water molecules pass through the cell membrane from an area of low solute concentration to high solute concentration. For example, if the cell is submerged in saltwater, water molecules move out of the cell. If a cell is submerged in freshwater, water molecules move into the cell.

[...]

The osmotic entry of water raises the turgor pressure exerted against the cell wall, until it equals the osmotic pressure, creating a steady state.

When a plant cell is placed in a solution that is hypertonic relative to the cytoplasm, water moves out of the cell and the cell shrinks. In doing so, the cell becomes flaccid. In extreme cases, the cell becomes plasmolyzed – the cell membrane disengages with the cell wall due to lack of water pressure on it.

When a plant cell is placed in a solution that is hypotonic relative to the cytoplasm, water moves into the cell and the cell swells to become turgid.

Osmosis is responsible for the ability of plant roots to draw water from the soil. Plants concentrate solutes in their root cells by active transport, and water enters the roots by osmosis. Osmosis is also responsible for controlling the movement of guard cells.

Osmosis can be demonstrated when potato slices are added to a high salt solution. The water from inside the potato moves out to the solution, causing the potato to shrink and to lose its 'turgor pressure'. The more concentrated the salt solution, the bigger the difference in size and weight of the potato slice.

In unusual environments, osmosis can be very harmful to organisms. For example, freshwater and saltwater aquarium fish placed in water of a different salinity than that to which they are adapted to will die quickly, and in the case of saltwater fish, dramatically. Another example of a harmful osmotic effect is the use of table salt to kill leeches and slugs.

Suppose an animal or a plant cell is placed in a solution of sugar or salt in water.

1. If the medium is hypotonic relative to the cell cytoplasm — the cell will gain water through osmosis.
2. If the medium is isotonic — there will be no net movement of water across the cell membrane.
3. If the medium is hypertonic relative to the cell cytoplasm — the cell will lose water by osmosis.

Essentially, this means that if a cell is put in a solution which has a solute concentration higher than its own, it will shrivel, and if it is put in a solution with a lower solute concentration than its own, the cell will swell and may even burst."
(https://en.wikipedia.org/wiki/Osmosis)

 

[Kassiopeija]

And:
"Root pressure: If the water potential of the root cells is more negative than that of the soil, usually due to high concentrations of solute, water can move by osmosis into the root from the soil."
(https://en.wikipedia.org/wiki/Xylem#Transpirational_pull)


The way I understand these texts is that low EC water will flow towards high-EC water because the high-EC water holds a greater chemical energy (fertilizer-ions) and "draws" that water to it.

One thing to realize (and this is actually where growbro Woody is wrong) is that a plants "internal EC" is/should always be higher than a (healthy) nutrient solution. [!]

Rainwater is EC 0.0 so it's not hard to envision that a fresh rainfall won't deliver a high-EC contect to outdoor plants, even if it takes up humic acids or mineralic content while it passes through the soil.
More than 90% of the water taken up by a plant will simply evaporate leaving behind the dissolved minerals/ fertilizer-ions and what not, so the EC has to rise inside a plant, esp. if the plant has to evaporate alot because of heat.

In my experience it's more easy to overfeed a plant that has to drink a lot because of the summer heat or strong light, esp. in combination with low rH.

The burnt tips at the end of the leafes is actually unused mineralic content that was left-over once all water did evaporate but the plant couldn't metabolize it all. Water and oxygen goes out, all the rest stays.

Then, if the nutrient solution is too high for the roots, the charged ions are actually trying to leech water out of the plant back into the pot - countering the evaporation pull causing the internal pressure to go down - you see the plant's leaves clawing, bending down, or drooping. Esp a seedling can die rather quickly bc of too high EC.

In the opposite case - if a plant has no trouble sucking in the water, or if the difference in EC is quite high so that osmosis will exert a great additional "thrust" additionally to the evaporation pull - you'll see the leaves stretch healthy upwards toward the light.

Yes mate I use tap water with a background of 0.2ec.

I wonder why you're not using pure water entirely? Because then you're having full control over the CalMag-ratio, plus you've ruled out any unknown factors that may be in that water. For example, some (esp. calcium) molecules are too big and a plant can't use it, but they'll still block the osmotic membrane. In an organic soil grow that doesn't matter much because the microbes will break that down but in mineralic hydro IDK....)

It could be many problems but initially the light needs to be futher away or that tacoing wont stop.

The damage i see is simply heat and reducing lights reduces leaf temperature which atm is an easy fix.

I had many issues and most were simply the environment - 600w hps are pretty big lights i struggled to get them very close whatsoever but the spread is pretty good

Agreed - one thing to keep in mind is that if a plant is in trouble the rate of photsynthesis it does will drop. So if one doesn't reduce the distance of such strong lamps - the photons will still be absorbed by the chloroplasts but heat them up instead of driving a chemical reactions - chloroplasts die. And you won't be able to feel such a heat with your hand, or directly measure it with your instrument because the destruction happens at a level that is even smaller than a single cell.

Your plant tells you it wants less light if it alters its leaves to face with less area towards that lamp - side of leaves curl upwards making "the saw" - although heat stress/ light stress can come from many sources:
Many assume it's bc of too much light, but actually a healthy cannabis plant can take a boatload of light because its genetic is used to the sun which will emit 125k lumens at the zenith.
My sativas can grow close to 25cm towards a good 600W HPS and still show no signs of bleaching/heat stress, however, they'll start foxtailing from onward 40cm. (I'm using an additional spreader directly under the lamp).
Foxtailing = more harvest but a longer flower, buds not as ripe as they could be, less bronze trichomes so that's ok for strains that should be more mental or make you too sleepy at the end...
BTW who got the biggest foxtails here? Is it true what I've been reading that they're not really approved by your legal customers over there?

Nizza is correct! Control the res or buckets to under 70 but not below 65 F.

pH... STOP allowing that pH to drop to 55 -

Plants look nice man but dont take my word for it the plant will produce more if the roots are the correct temperature. It would be so easy to get them to the right temperature too. Look it up yourself why 52-55 is too cold, raising your temp in the reservoir ten degrees could possibly create a new issue if the water isn't oxygenated enough.
Your lucky you can keep it that cold a chiller would cost alot

Not saying its detrimental but your yield will suffer because the plant could be metabolizing faster

Affirmative. Heat drives chemical reactions. If the roots are too cold it'll greatly decrease yield, classically happens to new LED growers that made the transition from HPS.
pH swings, great EC drops, basically everything that is a swift or dramatic change in the environment will force the plant having to readapt thus creating these "shocks". Avoid them as best you can bc plants like to dwell in homogeneity.

I'm reading lots of mineralic hydrogrowers are favorable towards using H2O2 in their solution in order to kill bacteria and get a bit more oxygen at the roots. A dam shame it won't work in an organic grow....

Drop me a line sometime and we can discuss how to manipulate terps and trich's. Increase THC or CBD levels.

I'd like to read your stance on this, it would be nice to have to a thread dedicated towards this specific subject.

Personally I'm operating under this guideline: (for watering)
- Seedling/Cut pH 6.2, CalMag to EC 0.15 ratio 5:1, food only in traces
- Veg pH 6.5, CalMag to EC 0.25 ratio 3:1, additional food to EC 0.7-1.2max
- Flower pH 6.8, CalMag to EC 0.4 ratio 2:1, add. food EC progressively from 1.2 to 2.1max
What do you think about these numbers in a really light soil?

What's the reason why pH should become more alkaline as the plant ages? I've read that before somewhere just can't find it now...

 

[Bigdickbigbud]

It may finally be getting through to me! The next few weeks will tell!

Every grow I am experiencing Calcium deficiency at around week 3-4 into flower and duly a less than optimum harvest. The cal deficiency escalates so I up my PH to over 6 and add more cal although I am sure they have enough (DWC by the way).
The leaves shrivel nearest the lights so I think maybe nute burn so drop my feed to 1.1 after a res change, nothing much changes and my grow turns out substandard.

My mate who is more experienced says I am feeding far to low, he feeds at well over 2.0 all be it in flood and drain and beats me hands down every grow even though he doesn't seem to care about things as much as I do, (green fingered ba$t&rd).

I have read some of Woody J's old threads on a UK forum (I believe he also posted on here) and hopefully it is finally sinking in.

I can see he makes sense but it goes against everything else I have read. " Static water level, Nute ec going up means you are feeding to high as the plants can't take any more nutrients so don't drink, reduce ec and plants will drink more then work your way up from there.

Woody's advice below

Most people assume that with a rising EC, it is the plants way of saying, I don't want more food, here, have some back.

What is actually happening is this.

Plants roots take in water/nutrients through a process called Osmosis. Effectively, if you think in terms of the roots having their own internal EC.
The osmosis process will always try to balance out the EC's, taking from the higher side of the barrier and giving to the lower part.

So if the EC of the nutrient solution is higher than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process.
"If however, the EC of the solution is lower than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution. "
A res change or increase in EC should resolve depending on the other factors such as ph and water levels.

So I am now thinking as calcium is semi mobile and I am feeding to low it is leeching from my roots and plants into the nutrient solution.

I will reword this sentence above "So I am now thinking as calcium is semi mobile and I am feeding to low it is leeching from my roots and plants into the nutrient solution"

I don't think it will be pulled from the plant as it is not truly mobile and cannot be trans-located I think maybe it cannot be up taken due to the plants equalizing their environment. Do I have this correct ?????

My problem has always been static ec and constant dropping PH (I have seen Woody's chart) with water/nutrient levels all over the place sometimes drinking then suddenly slowing for no reason.

Maybe I am feeding them at basic maintenance and as soon as full flower kicks in they are struggling.

I've been growing for nearly 3 years now all be it in 4 different systems but have only managed over gram watt on a few occasions. Am I missing something ??

I think you have an issue with oxygen in the water... Add a few more air stone pumps to the reserve and the pH should stabilise.
That to me is the issue and that's why it affects u at the stage it does because of root/oxygenated water ratio been off.
I had the same issue in an IWC 8pot system.. pH plummeting daily even though we fed by the book used all the right equipment and flushed the system almost daily by week 6.. we would return and the pH would be 4.5 av or lower sometimes... We added 2large airstones and the pH stabilised and the plants perked up and normalised.

All the best.. nothing worse than a below average crop and lackluster ladies!

 

[Vulcanofilo]

So whats going on?

So whats going on?

Hello from Spain,

Casi seguro tienes un virus, cuchara, mosaico, o varios juntos,. Es por eso que fracasas cada vez, y confundes con carencias.

Muy común y cada vez mas Visto.

Haz pruebas

 

[Dr. Who]

And:
I'd like to read your stance on this, it would be nice to have to a thread dedicated towards this specific subject.

Personally I'm operating under this guideline: (for watering)
- Seedling/Cut pH 6.2, CalMag to EC 0.15 ratio 5:1, food only in traces
- Veg pH 6.5, CalMag to EC 0.25 ratio 3:1, additional food to EC 0.7-1.2max
- Flower pH 6.8, CalMag to EC 0.4 ratio 2:1, add. food EC progressively from 1.2 to 2.1max
What do you think about these numbers in a really light soil?

What's the reason why pH should become more alkaline as the plant ages? I've read that before somewhere just can't find it now...

Slightly higher pH in bloom? Enhances the availability of the P, while decreasing the availability of N. However slightly, it is a plus in growing by hand to follow that.

S when delivered by differing forms of sulfate, effect terps. At least 2 of these sulfate forms. Will also increase some trich production.

Effecting THC/CBD concentrations, is the purvey of amounts of available Mn and Fe respectively.
These are to be closely controlled to amounts available by ppm in soil testing. I would suspect the same true for hydro availability amounts by ppm.

Higher Fe, over Mn gets you more CBD
Equal to slightly higher Mn get you more THC

In soil your available PPM goals to reach are 100 ppm each, maybe some slightly higher Mn. If it's CBD you wish to increase. Decrease Mn by 25%.

This is a very basic look at the use of these things for the reasons I gave. The underlying things you need to know about trying this stuff is more complex and has "rules" to follow so it does not have adverse effects. It is easy to slip and screw it up.
Amounts are exact and for some things, time(ing) of availability is critical.

 

[fartoblue]

OK. After reading the whole thread, and looking close....

I have several issues you should address.

Nizza is correct! Control the res or buckets to under 70 but not below 65 F.

pH... STOP allowing that pH to drop to 55 - AS BEST YOU CAN... This is better controlled by setting the pH to 6.2 or 6.3 in the mourning.
I know many who like low pH in hydro BUT, it is easy for it to lead to issues...just like yours. ESPECIALLY SINCE THE pH SHOULD BE A CPL OF TENTHS HIGHER IN BLOOM! Your way to low for blooming cannabis in hydro.
Rule of thumb in hydro applications for pH values... 5.7 to 6.3 The common quality book scale is 5.8 to 6.2.....
Part of the above issue is likely a habit of not dumping and starting with fresh nutrient mix properly. The other side of that coin is how much in concentration your adding back to "top off" the tank or buckets...

Waste build-up from the plant effects the ability of the mix in the bucket to work properly..

Lets take a look at a simple solution to that. "The 33% add back rule"
This is an old school, original hydro rule that still works well today!

Fill your res/bucket with your 100% feed solution. Note how much in volume you filled it with.
Now as that res/bucket reduces in solution, you add back to top off,,,correct? Keeping track of how much your adding back..

You should be adding back a 33% concentration of that feed solution and not 100%...

To make a 33% solution: Simply take a gallon of the 100% solution and add two (2) more gallons of plain water to it. You now have a 33% solution.

Top off using that 33% solution.
Now here's the other important part. Remember I asked you to keep track of how much your adding back?
Now when the amount you would add back comes to equal the amount you filled the res/bucket with the first time.
DUMP AND REFILL WITH 100% SOLUTION and restart the whole topping off with 33% all over again.

Do this in veg AND bloom!

Lastly: Mixing
Add each chemical after adding an amount of water.
EXAMPLE: Your making 3 gallons of 100% mix.
Add 4 cups of water to your mixing container.
Add the first chem by pouring the next 4 cup scoop over the measuring cup with the chem in it.
Rinse the measuring cup (I use a 60ml mini cup)
Now do the same for the each chemical you add. ALWAYS ADD THE CAL/MAG LAST.
Now pH your solution and use it.

I get the distinct feeling your not dumping and refilling enough and are suffering from hydro waste build-up..

This sure won't hurt you, so give it a big try out.

Good luck!

I am just about to put some plants into flower and will; be following your advice given in my thread.

I am just thinking about the 33% add back and would be grateful if you could advise. I just need to know the reasoning.

If I fill my 200 liter res at an optimum nutrient strength for say, week 4 of flower @ 1.5 ec excluding background. I then add back as the plants drink at 33% strength for around a week or until I have added back 200 litres @ 0.5 ec , is this correct?

What I don't understand is if 1.5 ec is optimum for week 4 and I add back at 0.5ec will this not weaken the feed and take it below the optimum ec levels?

Many thanks

 

[Dr. Who]

I am just about to put some plants into flower and will; be following your advice given in my thread.

I am just thinking about the 33% add back and would be grateful if you could advise. I just need to know the reasoning.

If I fill my 200 liter res at an optimum nutrient strength for say, week 4 of flower @ 1.5 ec excluding background. I then add back as the plants drink at 33% strength for around a week or until I have added back 200 litres @ 0.5 ec , is this correct?

What I don't understand is if 1.5 ec is optimum for week 4 and I add back at 0.5ec will this not weaken the feed and take it below the optimum ec levels?

Many thanks

The plant is actually using about that 33% as it grows. SO, in reality, your not doing much but actually adding back what the plant use's.

You can see now how adding back more then 50% can lead to some real issues.
There are many factors in hydro that can effect how the plant use's the available feed.
PPM content of the water you use has a huge effect. Simple rule of hydro thumb and quality control. Do NOT use any water at 150 ppm or higher.

Your best ability to control exactly what you feed and how the plant reacts? Use RO water at <10ppm...

I run nothing but RO in any style of grow I do. I have found rain water to be too variable and not available in the cold months....
Better to have my water source as "CONSISTENT".

 

[fartoblue]

The plant is actually using about that 33% as it grows. SO, in reality, your not doing much but actually adding back what the plant use's.

You can see now how adding back more then 50% can lead to some real issues.
There are many factors in hydro that can effect how the plant use's the available feed.
PPM content of the water you use has a huge effect. Simple rule of hydro thumb and quality control. Do NOT use any water at 150 ppm or higher.

Your best ability to control exactly what you feed and how the plant reacts? Use RO water at <10ppm...

I run nothing but RO in any style of grow I do. I have found rain water to be too variable and not available in the cold months....
Better to have my water source as "CONSISTENT".

I'm with you now DW, many thanks.

Luckily for me my water comes out of the tap (faucet) @100ppm or less, occasionally won't even register. I live out in the sticks, UK.

 

[fartoblue]

The plant is actually using about that 33% as it grows. SO, in reality, your not doing much but actually adding back what the plant use's.

You can see now how adding back more then 50% can lead to some real issues.
There are many factors in hydro that can effect how the plant use's the available feed.
PPM content of the water you use has a huge effect. Simple rule of hydro thumb and quality control. Do NOT use any water at 150 ppm or higher.

Your best ability to control exactly what you feed and how the plant reacts? Use RO water at <10ppm...

I run nothing but RO in any style of grow I do. I have found rain water to be too variable and not available in the cold months....
Better to have my water source as "CONSISTENT".

Hope you don't mind a quick question DW. I have just added 1/3 strength to my holding tank which is more or less the same size as my system so it is handy.

When I make up the 1/3 strength batch into my 200 litre holding tank do I also add silica acid and root stimulator and Cal/mag @ 1/3 strength or full?
I added the cal/mag at full strength for this batch and the root stim and silica @1/3 but can change it if I need full?

If the nute strength goes down in my system do I just let it ride and go in at full strength when I change the res or do I add more nutes directly to the main system?

 

[Dr. Who]

Hope you don't mind a quick question DW. I have just added 1/3 strength to my holding tank which is more or less the same size as my system so it is handy.

When I make up the 1/3 strength batch into my 200 litre holding tank do I also add silica acid and root stimulator and Cal/mag @ 1/3 strength or full?
I added the cal/mag at full strength for this batch and the root stim and silica @1/3 but can change it if I need full?

If the nute strength goes down in my system do I just let it ride and go in at full strength when I change the res or do I add more nutes directly to the main system?

When you reach the amount of total add backs - to equal the original amount of 100% you filled the res with...
Dump and refill with a new batch of 100% solution and restart the 33% add back till you hit that original amount again.

Fill 100% - add back 33% as needed - reach the same amount added back as you filled the first time.....Dump, refill with 100% and start over.