How do I feed my RDWC plants? + EC/PPM/PH

SmokeyMcChokey

Well-Known Member
Yep just in 15 years i never had one that made my res ph go down lol i thought i had some problems ha ha .

Gh,botanicare,advanced , all make the ph rise when set at 5.8 . At least thats what i ran for 15 years lol
My old tap water and the fox farm stuff used to raise mine over time. Who knows if it was supposed to as it was a decade ago and only on one run. In fact I just found the old pint bottle of gh pH up in a box during my last clean out. Still half full. I always found the pH up waskre potent than down.
 

justsmokedope

Well-Known Member
i find with my rdwc undercurrent system that you don't need a really strong nutrient solution like other systems as the circulation in the system makes the nutrients flow past the roots and helps nutrient up take and can save you money in nutrants . i don't find ph ec issues an issue either due to the volume of the water in the system . if you can cool the solution this helps with disolved oxygen and growth also .
i would advise adding Canna Cannazym as this eats dead roots etc and keeps root balls healthy
 

Cold$moke

Well-Known Member
Actually i had a thread going on root pruning exp.

I will be doing some form of early pruning almost exclusively after another try to set it in stone.

It made my clone stay tiny but grew a huge root nub.....then when i finally let the roots grow the little things took the fuck off lol

So im going to try it again with only about 2 weeks devoted to root pruning my clones for production as long as the results are the same i am sold :)

At the very least im sure not affraid to nip the ends any more.

From what i observed when you cut a root its just like the top it goes lateral after that .

But you are correct in saying it will slow the plant down how much depends on how much root you cut and how happy the plant is .

Basically i was getting an inch or 2 of new root growth every day when i would snip them

And they just kept getting denser and denser

This is also why now i immediately check the root zone when i see issues in the plant
 

Cold$moke

Well-Known Member
Root pruning definitely works in my situation

With a small veg room it keeps the above ground plant going slow but the root is getting huge

So when i finally throw it in bloom it takes off
And still stays short enough to work training in.

Ill know more after the second round of experiments ;)
 

HydroRed

Well-Known Member
Root pruning definitely works in my situation

With a small veg room it keeps the above ground plant going slow but the root is getting huge

So when i finally throw it in bloom it takes off
And still stays short enough to work training in.

Ill know more after the second round of experiments ;)
Though I dont have much experience in this, I just recently pruned the hell out of the roots on a plant that had just been harvested. It was getting transplanted and put back into veg to keep as a momma. Cant speak on vegging or it stalling growth, but it seemed to encourage new roots to form once transplanted? I had new roots within 5-6 days. Not to mention, I run a sterile res so the less old/dead/decaying roots the better.
 

Budley Doright

Well-Known Member
I was trimming them to keep them out of drain and every time I did the plant stalled but I guess it could have been perception :(. I now use silkscreen to cover all the drains and it works but does need periodic back washing. I grow indoors as fast as I can and try to flip them over quick so any delay hurts lol. I try to beat the heat but I’ll be into it this run, hopefully it will be done Mid June :(
 

Cold$moke

Well-Known Member
There are some badass root videos on the tube
That show how a root knows which way is down .

Also check out dr whitcomb :) root pruning

I will say that after about 3 straight weeks of pruning daily it finally started to piss off the top growth a little (rust spots) and so thats about when i stopped i think id have to check dates.


But when you cut a root system it grows laterally
Until the root tips start going down again

Basically it makes fish bone roots that continue on to become main roots

This pic was a few days after being rooted i think mabey a week from cut .
Dont mind the black shit it was kelp and humic acid :)20180115_215027-1.jpg
8 days later sniping at roughly the same length
20180123_115602.jpg
 

joecanna17

Well-Known Member
First time grower here using RDWC. Since this is my first grow ever I have a lot of questions so bare with me everyone lol. Also, not sure if it makes a difference but my system consists of 6 5-gallon home depot buckets connected to a 12.5 rez. I appreciate any help/advice you can give. bongsmilie :weed: :-D

1. Do I only feed once per week during water changes?

2. Do I mix the nutes together like a cocktail and pour it in the reservoir?

3. What should my EC/PPM/PH look like throughout the grow? I have an R.O. Machine (HydroLogic 150)

4. How often should I check EC/PPM/PH?

5. Ive heard too many nutes for young clones can burn them, so whats the right amount for them?

6. What nutrients would you recommend for RDWC?
Wow, sorry your thread is so full of dickbags, @tookablunts . Seems they'd rather spend more time slinging shit than it would take to answer a few questions.

I'll try to give you the best answers in general terms as I can. Keep in mind, your results may (probably will) vary. Your environment is yours alone, and you'll learn to deal with it. Nobody can give you specific answers for your environment, but we can give you general guidelines.

Kudos to you for jumping in head first, and trying one of the more feared cultivation styles from the get-go! (It's not actually as scary as most make it out to be.)

Now on to all those questions...

1. Yes, with RDWC,you generally feed with a new reservoir filling, and top off with plain water as it drops, until it's time for a rez(reservoir) change. You'll top off with plain water so that nutrient concentration doesn't build up between rez changes. How often you change the rez will depend on your specific environmental conditions, and how often you want to dump water and nutes.

2. No, don't mix your nutes all together before adding to your rez, if that's what you meant by "like a cocktail".
I turn the circulation pump on while I'm adding nutes, to keep everything flowing . Add all nutes and additives to circulating system.
Generally, you want to add your silica supplement first. A lot of times, it doesn't mix well after adding certain lines of nutes. Bonds to certain elements, causing them to fall from suspension.
Next, add beneficial bacteria, if you're running a live system.
Next, add root conditioners, SM90,etc...
Then add your nutrients to the levels you want.
Last, add you pH up or down to target ph

3. Your ph should be between 5.5 and 6.0 for hydro. 5.5-6.5 for hydro or soil generally, but they'll survive from 5 to 7at least. Keep in mind, every .1 difference is 100x more concentrated, if I remember correctly.

On a digital ec/ppm meter, there will usually be two scales: 500 and 700. Most people seem to use the 500 scale, which converts pretty easily to ppms. i.e. 500ppm = 1.0ec. The 700 scale isn't much harder, but I don't remember it offhand.

So, your ph should be 5.5-6.0 throughout. Now, your ppms/ec needs will vary through phases of life, and especially with different strains, if you've got a wide variety. A sativa or more tropical strain will require less food than a mountainous indica strain, in general. If you're running modern poly-hybrids like most though, they should probably be in the same ballpark, foodwise. Now, if you're using some new school LED lights rather than HPS or MH, your nutrient needs will be a bit higher as well, regardless of strain.

That being said, here are some approximate guidelines for ppms in different phases of life:
Seedling / Unrooted Clones: ~1/4 suggested strength, about 100-300ppm
Established seedlings / rooted clones: ~1/3-1/2 suggested strength, about 3-500pmm
Teens / Preflowers: ~1/2-3/4 strength, about 5-700ppm
Early Flower w1-3:Flower nutes may be different, depending on brand used. Early flowering is usually same or slightly higher than late veg. Appx 700-1000ppm
Mid Flower w4-6: 500-1000ppm
Late Flower: w7-8: 300-700ppm, if strains run more than 8wks...top off with water only, if 8wk strains.
**You may need slightly more nutes, if running RO water, as well.

4. As a newbie, it's not a bad idea to get into the habit of monitoring your system to keep things in check. You probably don't need to check twice a day as suggested, but I would recommend once for sure, just to get into the habit of checking things out, and watching the pattern of how the plants feed, and what happens to ppm and ph. As you get comfortable with your system, you'll probably check less often, and only when you need to.

5. Yes, too many nutes for any stage of life can be dangerous, but if you follow the general guidelines above, you should be fine. Give unrooted clones, or seedlings, ~1/4 strength or ~100-300ppm of nutes.

6. This question should probably be answered in your mind, before asking most of the previous questions, really. There are tons of different nutrients out there, and you'll probably end up trying a few before settling on one you like. I've always been a fan of simplicity, and for the last few years, I've been using the Ionic line, which is a 3 part, liquid solution.
Always striving for simplicity, however, I'm about to try out some Greenleaf MegaCrop. From what I've been reading on the threads, everyone who's chimed in is happy with their results, and it's a 1 part powdered solution with just about everything you need. Same stuff from seedling to finish, just in different amounts. The fact that they're literally giving the stuff away doesn't hurt. You can always get 230 gram sample for free, with shipping (~$3)...but right now they're giving away 1000g until at least 4/20. Shipping here for 1000g was ~$6.50.
I recommended this nutrient to a new patient based on simplicity, but more importantly, others apparent results.

I hope this has helped answer some of your questions. Let us know how the build goes, and if there's more details you need straightened out...
 

joecanna17

Well-Known Member
If he researches he wont have to depend on forum info ;) not saying your wrong

dick bag :)
LOL Oh, I know....I'm sure pretty much any question that could be asked is answered somewhere here. I just figured since he had a few specific questions, we could help him out a bit. No need to scare the newbs away before they get a chance to rot a few roots :lol:
 

joecanna17

Well-Known Member
@joecanna17 Why would he add back plain water? Should it not be what the original EC and ph was? If he adds back plain water would he not end up with 0ec?
The reason I like to add back plain water is that we don't know exactly how much of each nutrient the plants use as the time goes. I'd rather let the nute level slowly drop until the next fresh rez change, than add back nutes to unknown ratios left in the rez. You could potentially overdose with nitrogen, for example, if the plants aren't uptaking nitrogen at the same rate they are other elements.

Of course he'll want to keep an eye on ppm and ph levels throughout, but through the week or two between rez changes, I wouldn't add back food, just ph up or down, if needed.

I highly doubt he'll get down to 0ppm/ec within a week or two, even adding plain water, from experience.
 

SmokeyMcChokey

Well-Known Member
Wow, sorry your thread is so full of dickbags, @tookablunts . Seems they'd rather spend more time slinging shit than it would take to answer a few questions.

I'll try to give you the best answers in general terms as I can. Keep in mind, your results may (probably will) vary. Your environment is yours alone, and you'll learn to deal with it. Nobody can give you specific answers for your environment, but we can give you general guidelines.

Kudos to you for jumping in head first, and trying one of the more feared cultivation styles from the get-go! (It's not actually as scary as most make it out to be.)

Now on to all those questions...

1. Yes, with RDWC,you generally feed with a new reservoir filling, and top off with plain water as it drops, until it's time for a rez(reservoir) change. You'll top off with plain water so that nutrient concentration doesn't build up between rez changes. How often you change the rez will depend on your specific environmental conditions, and how often you want to dump water and nutes.

2. No, don't mix your nutes all together before adding to your rez, if that's what you meant by "like a cocktail".
I turn the circulation pump on while I'm adding nutes, to keep everything flowing . Add all nutes and additives to circulating system.
Generally, you want to add your silica supplement first. A lot of times, it doesn't mix well after adding certain lines of nutes. Bonds to certain elements, causing them to fall from suspension.
Next, add beneficial bacteria, if you're running a live system.
Next, add root conditioners, SM90,etc...
Then add your nutrients to the levels you want.
Last, add you pH up or down to target ph

3. Your ph should be between 5.5 and 6.0 for hydro. 5.5-6.5 for hydro or soil generally, but they'll survive from 5 to 7at least. Keep in mind, every .1 difference is 100x more concentrated, if I remember correctly.

On a digital ec/ppm meter, there will usually be two scales: 500 and 700. Most people seem to use the 500 scale, which converts pretty easily to ppms. i.e. 500ppm = 1.0ec. The 700 scale isn't much harder, but I don't remember it offhand.

So, your ph should be 5.5-6.0 throughout. Now, your ppms/ec needs will vary through phases of life, and especially with different strains, if you've got a wide variety. A sativa or more tropical strain will require less food than a mountainous indica strain, in general. If you're running modern poly-hybrids like most though, they should probably be in the same ballpark, foodwise. Now, if you're using some new school LED lights rather than HPS or MH, your nutrient needs will be a bit higher as well, regardless of strain.

That being said, here are some approximate guidelines for ppms in different phases of life:
Seedling / Unrooted Clones: ~1/4 suggested strength, about 100-300ppm
Established seedlings / rooted clones: ~1/3-1/2 suggested strength, about 3-500pmm
Teens / Preflowers: ~1/2-3/4 strength, about 5-700ppm
Early Flower w1-3:Flower nutes may be different, depending on brand used. Early flowering is usually same or slightly higher than late veg. Appx 700-1000ppm
Mid Flower w4-6: 500-1000ppm
Late Flower: w7-8: 300-700ppm, if strains run more than 8wks...top off with water only, if 8wk strains.
**You may need slightly more nutes, if running RO water, as well.

4. As a newbie, it's not a bad idea to get into the habit of monitoring your system to keep things in check. You probably don't need to check twice a day as suggested, but I would recommend once for sure, just to get into the habit of checking things out, and watching the pattern of how the plants feed, and what happens to ppm and ph. As you get comfortable with your system, you'll probably check less often, and only when you need to.

5. Yes, too many nutes for any stage of life can be dangerous, but if you follow the general guidelines above, you should be fine. Give unrooted clones, or seedlings, ~1/4 strength or ~100-300ppm of nutes.

6. This question should probably be answered in your mind, before asking most of the previous questions, really. There are tons of different nutrients out there, and you'll probably end up trying a few before settling on one you like. I've always been a fan of simplicity, and for the last few years, I've been using the Ionic line, which is a 3 part, liquid solution.
Always striving for simplicity, however, I'm about to try out some Greenleaf MegaCrop. From what I've been reading on the threads, everyone who's chimed in is happy with their results, and it's a 1 part powdered solution with just about everything you need. Same stuff from seedling to finish, just in different amounts. The fact that they're literally giving the stuff away doesn't hurt. You can always get 230 gram sample for free, with shipping (~$3)...but right now they're giving away 1000g until at least 4/20. Shipping here for 1000g was ~$6.50.
I recommended this nutrient to a new patient based on simplicity, but more importantly, others apparent results.

I hope this has helped answer some of your questions. Let us know how the build goes, and if there's more details you need straightened out...
Don't pander to the lazy or ignorant...
 

SmokeyMcChokey

Well-Known Member
The reason I like to add back plain water is that we don't know exactly how much of each nutrient the plants use as the time goes. I'd rather let the nute level slowly drop until the next fresh rez change, than add back nutes to unknown ratios left in the rez. You could potentially overdose with nitrogen, for example, if the plants aren't uptaking nitrogen at the same rate they are other elements.

Of course he'll want to keep an eye on ppm and ph levels throughout, but through the week or two between rez changes, I wouldn't add back food, just ph up or down, if needed.

I highly doubt he'll get down to 0ppm/ec within a week or two, even adding plain water, from experience.
Also I could be wrong but seem to remember that nitrogen will continue to be absorbed at a rapid rate well into toxicity. So yeah I add back plain to a degree as well. If in say a week my ppm has halved I'll add back a 75% strength mixture just to get by for another week or so. I do res change every 2 to 3 weeks
 

joecanna17

Well-Known Member
Also I could be wrong but seem to remember that nitrogen will continue to be absorbed at a rapid rate well into toxicity. So yeah I add back plain to a degree as well. If in say a week my ppm has halved I'll add back a 75% strength mixture just to get by for another week or so. I do res change every 2 to 3 weeks
Yeah, I'm sure he could do the same, and be fine. I'm just trying to keep it relatively simple and straightforward for a first timer. I doubt he has the equipment to check each element in his mix to see exactly what's needed mid-week, so topping off with more nutes with the original ratios could give him too much of one element or another, especially if the plants are already uptaking that element slower than others. Nitrogen was just an example, because, frankly, it was the first in line in my mind.
That's why I personally prefer just water until the next proper change. Let the plants use what they need, maybe even get a little hungry for a day or 2, then refill with your known formula.

Of course, if he ran a rez for weeks, or perpetually, he'd have to maintain it like you're saying. I'd just recommend for him to try and do weekly clean swaps of the rez, to get in the habit and keep a better eye on things while he's new.

I'd imagine as he gets comfortable with his system, he'll be doing more maintenance, less rez changes, like a lot of us end up doing lol
 

fartoblue

Well-Known Member
Well lads after serving my time growing coco for 2 years i decided to change to RDWC.

After burning the shit out of my seedlings thought I would research recommended ec for RDWC. Low and behold my research brought me to this page. Unfortunately the first 3 pages were a complete waste of time. Thankyou joecanna17 for not being to far up your own Arse to help those of us who are new to RDWC.

The undercurrent site is fantastic as mentioned but not all that much info on the web regarding RDWC feeding advice. I have decided to stick with the UC feed strengths although am using Shogun nutes.

I also nèed some advise if you could be so kind. Living in the north uk in the winter if the water pipes arnt frozen the water is extremely cold. My question is how do I do a res change without shocking the plants with ice cold water. I have 2 seperate 8 pot systems, one for veg one for flower. The flower system is 8 X 45 litre tubs with same size epicenter and a larger tank feeding the epicenter.

I am still in the veg system just now but will need to move them in next few days. I can't get hot water to my grow room unless I lug it in buckets. I have aquarium heaters to get the water up to temperature and keep it there but it takes hours.
 
Last edited:

TIMtoKILL

Active Member
Well lads after serving my time growing coco for 2 years i decided to change to RDWC.

After burning the shit out of my seedlings thought I would research recommended ec for RDWC. Low and behold my research brought me to this page. Unfortunately the first 3 pages were a complete waste of time. Thankyou joecanna17 for not being to far up your own Arse to help those of us who are new to RDWC.

The undercurrent site is fantastic as mentioned but not all that much info on the web regarding RDWC feeding advice. I have decided to stick with the UC feed strengths although am using Shogun nutes.

I also nèed some advise if you could be so kind. Living in the north uk in the winter if the water pipes arnt frozen the water is extremely cold. My question is how do I do a res change without shocking the plants with ice cold water. I have 2 seperate 8 pot systems, one for veg one for flower. The flower system is 8 X 45 litre tubs with same size epicenter and a larger tank feeding the epicenter.

I am still in the veg system just now but will need to move them in next few days. I can't get hot water to my grow room unless I lug it in buckets. I have aquarium heaters to get the water up to temperature and keep it there but it takes hours.

Make your own post. Don’t jump on one from March.....
 
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