Led grow yellowing and burn help please
- Thread starter Plarntmarn16
- Start date
1800 ppm way too high for those small plants to start. Id say about 1000 ppm shud b plenty at that size. 2nd burn usually appears on the top of plants not the bottoms. Deficiencies esp of immobile nutrients appear which is what you are seeing.
But that definetely isnt nutrient burn I dont think from what the pictures look like. That primarily looks like a magnesium deficiency.
What base nutrients are u using? U shud be running 5 ml / gallon of cal mag. That should def fix some of the problems to start.
Plarntmarn16
Member
I'm using general hydro flora nova grow and general hydro calimag at 1ml per litre. Lately I ha e been mixing my nutes at 22ec because my water is .230 so that would bring it back down to 20 ec and I was told by my hydro guy that is good but obviously not. ATM I'm flushing and will let you guys know how I go. Thanks for all the tips it's much appreciated. Cheers.
First hold on a second my man. What conversion is that?? What is the EC or PPM using either 0.5 or 0.7 as the conversion rate?
Before u go and do anything just check your medium ec(ppm) and the ph at the roots. Do this by running regular water at 7.0 ph thru your root zone and collecting the first 5-10% of the run off before proceeding on doing anyhing, you dont want to make shit worse!! If u run 7.0 ph water and your run off is say 5.0 than your gonna need to run higher ph water thru ur root zone until u can get back up to desired ph range. That is the first thing I would be checking. Also check the salt content of that runoff with ppm/ec meter or truncheon whatever you are using to measure nutrient solutions.
If the ph is fine but there is high ec/ppm in run off than go and begin to Flush your containers with 1/4 strength nutrients not plain water Including the cali magic.
in mean time i would be foliar spraying weak nutrient solution and magnesium product like cutting edge mag amp (magnesium) and plant amp(calcium) these are fastest and easiest absorbing cal mag i know of. If u cant get these just use cal mag foliar spray plant to help while your flushing the medium.
After you flush your medium and the ph is back to normal and the ppm/ec is in an acceptable range than go back to mild feedings and see how the plants react.
Just start adding 5 ml/gallon of the cali magic. And use half strength of the flora nova grow if its says use 20 ml/gallon use like 10-12 with the calmag at 5 ml/gallon.
What else are you giving your plants anything? What week of veg are you in right now?
Plarntmarn16
Member
my ec metre just reads in milli or micro ec all it does is change the decimal. I don't convert anything.
Damn I just emptied half my res tank and topped up with ph 5.9 plain water.
My nutes are now at 1100 ec and my water was 260 does that mean my actual nute strength is 840?
Also I ran the fresh 5.9ph water through my pots which was 25lites in total so I'm guessing all the salts and ph would now be totally gone and I'll basically have just the ec reading of fresh water and ph of 5.9 if I did the run off testing?
Damn I just emptied half my res tank and topped up with ph 5.9 plain water.
My nutes are now at 1100 ec and my water was 260 does that mean my actual nute strength is 840?
Also I ran the fresh 5.9ph water through my pots which was 25lites in total so I'm guessing all the salts and ph would now be totally gone and I'll basically have just the ec reading of fresh water and ph of 5.9 if I did the run off testing?
Plarntmarn16
Member
Sorry if I confused you by jumping from micro to milli ec. I'll stick to micro from now on
Oh I was confused by an earlier post I thought you were in a different medium. So your running a flood and drain hydroponic system than. You also said you were running R/O how is your water 250 ppm?
Just use straight R/O dont mix it with tap or well water. Start with 0 ppm and add 5 ml/gal of cal mag, and use 1/3 to 1/2 strength flora grow. You should have ppm of around 800 ppm doing this.
And you said you are running hydroton correct? So I would than make your ph in your main reservoir to 5.6 ph. I wouldnt start with a ph of 5.9 because ph drifts and will most likely be out of range in a few hours. So start a little lower and let it drift up. As the water is absorbed and nutrient concentration goes up the ph will go back down. So make sure you have 1/4 strength top off water maybe about 350-400 ppm of 2-3 ml cal-mag and 5-6 ml of flora grow to replace water and nutrients that are absorbed when roughly 1/4 of the main reservoir is depleted. Just test the water after a couple days and see what the ph and ppm of the nutrient solution in your reservoir is so you can see how much they plants are using each day or every few days.
This is important to know so you can make sure your plants are absorbing and using nutrients correctly and your ph is stable and not swinging drastically.
Also temperature and humidity have a major impact on what amount of nutrients you are providing your plants. If your temperature is higher above say 80 F than you want to reduce your nitrogen 10-15% because the plants will be using more water to transpire and keep cool. When your temperatures are lower say low 70's than the opposite is true. Since less water is needed to cool and transpire you will want to use a stronger solution since the plants will be slowly absorbing water.
This is the law of thermo dynamics and osmotic pressure in your root zone. You dont want to get an anaerobic environment in your root zone which will throw off the uptake of nutrients to water. Too much water absorbed creates toxic levels of salt, and not enough water and nutrients causes deficiencies. Its got to be balanced with your environment!!
Make sure that your reservoir water is in the 67-70F temperature range as well. Outside of that range can cause depletion of oxygen and lead to bacteria and fungus in your root zone. If its too cold it can lock out nutrients causing a deficiency to occur. So make sure you are providing the right environment for your plants. Ambient temp of 75-80 degrees and RH of 60%. And root zone temp between 67-70 F.
You do have a top off for water that evaporates I hope? If u dont what are you doing when the reservoir water is being used? This could be your issue if you arent topping off and keeping your main reservoir you are feeding your plants with in the proper range.
At this point I would run only 5ml/gallon of cal mag and 1/4 strength nutrients for a few days at ph of 5.6
After a few days see how they respond. Than you can up the base nutrient to 10 ml/gallon after like 3-5 days if you see improvement.
To answer your question though. Yes if your starting water is 250 and your ppm is 1100 than you are adding in 850 ppm of nutrients. Since you have an R/O I would just make all the water and just use that so you can know exactly what you are giving your girls. Every water source is different so starting with 0 and no dissolved solid in your water gives you full control and you will be better off at the end of the day.
Plarntmarn16
Member
Firstly thanks heaps for your time mate I appreciate it!
Nah I don't have ro water but I think I will be investing in one for sure! I will follow your instructions and see how I go. My ph used to go up quickly but lately it has stabilised my temps are good, between 18 at lights off and 26 at lights on max. My rh is between 40 and 70
And at the moment my ec is 950.
Nah I don't have ro water but I think I will be investing in one for sure! I will follow your instructions and see how I go. My ph used to go up quickly but lately it has stabilised my temps are good, between 18 at lights off and 26 at lights on max. My rh is between 40 and 70
And at the moment my ec is 950.
Tim Fox
Well-Known Member
getting some good help over here,, right on