Help RDWC, Leaf Tips Curling & Twisting Leafs

[Danner]

These two plants were just switched from a bubbler into a RDWC system I built a few days ago and can't figure out what's going on. This is my 2nd grow and first attempt at hydro. Along with transferring into the RDWC I switched lighting from 18/6 to 12/12 on Saturday (they were vegged for 42 days). One is Gods Gift and the other is Aurora. The leafs on the Gods Gift are yellowing and the leaf tips are curling down. The Aurora is also starting to yellow, leaf tips are starting to curl down slightly, and one of the leafs has twisted. Its a 3 bucket RDWC system using 5-gallon buckets, one is a control bucket, hooked together with 2" pvc and a 3/4" return line with a 382 gph inline pump set at 15 on / 15 off. There's currently about 10-12 gallons total.

Room Size: 5x7
Lighting: 1000w hps on 12/12 (20" above canopy)
Nutes: FloraNova Series following GH feed schedule
PPM: 1100 (2.5ml grow; 2.5ml bloom; 1ml Rapid Start; 1ml Floralicious; 1ml Superthrive)
*PH: Range from 5.6 - 5.9
Water Temp: 64 - 74 (using frozen water bottles and typically staying around 70)
Air Pump: 110 lpm
Room Temp: 63 - 77
RH: 35% - 55%
Ventilation: 435 cfm fan dialed down to about 25-30%

The only problem I've had has been with my PH meter so I'm thinking this may be a PH problem. My Nutradip Tri-Meter started giving me erratic readings out of nowhere the other night, so I went and bought a cheap PH pen, but I don't know how accurate the pen is. I think I fixed the tri-meter but the odd thing is that when both meters are calibrated the pen reads 0.4 - 0.5 higher than the tri-meter, consistently. I don't know which meter to trust. I think the tri-meter is giving me the correct readings and the PH range I listed above is based on the tri-meter readings.

Gods Gift - Yellowing Leaves and Leaf Tips Curling/Hooking Down:

Aurora - Yellowing Leaves - Leaf tips Curling/Hooking slightly - Twisted Leaf:

The twisted leaf is the only one on this plant that has done that, but in general, all the new growth on these plants look light green/yellow and look weak (i.e., thin and under-developed for lack of a better word). Any help, opinions, or suggestions is greatly appreciated.

Thank you!!

 

[jlt1202]

These two plants were just switched from a bubbler into a RDWC system I built a few days ago and can't figure out what's going on. This is my 2nd grow and first attempt at hydro. Along with transferring into the RDWC I switched lighting from 18/6 to 12/12 on Saturday (they were vegged for 42 days). One is Gods Gift and the other is Aurora. The leafs on the Gods Gift are yellowing and the leaf tips are curling down. The Aurora is also starting to yellow, leaf tips are starting to curl down slightly, and one of the leafs has twisted. Its a 3 bucket RDWC system using 5-gallon buckets, one is a control bucket, hooked together with 2" pvc and a 3/4" return line with a 382 gph inline pump set at 15 on / 15 off. There's currently about 10-12 gallons total.

Room Size: 5x7
Lighting: 1000w hps on 12/12 (20" above canopy)
Nutes: FloraNova Series following GH feed schedule
PPM: 1100 (2.5ml grow; 2.5ml bloom; 1ml Rapid Start; 1ml Floralicious; 1ml Superthrive)
*PH: Range from 5.6 - 5.9
Water Temp: 64 - 74 (using frozen water bottles and typically staying around 70)
Air Pump: 110 lpm
Room Temp: 63 - 77
RH: 35% - 55%
Ventilation: 435 cfm fan dialed down to about 25-30%

The only problem I've had has been with my PH meter so I'm thinking this may be a PH problem. My Nutradip Tri-Meter started giving me erratic readings out of nowhere the other night, so I went and bought a cheap PH pen, but I don't know how accurate the pen is. I think I fixed the tri-meter but the odd thing is that when both meters are calibrated the pen reads 0.4 - 0.5 higher than the tri-meter, consistently. I don't know which meter to trust. I think the tri-meter is giving me the correct readings and the PH range I listed above is based on the tri-meter readings.

The twisted leaf is the only one on this plant that has done that, but in general, all the new growth on these plants look light green/yellow and look weak (i.e., thin and under-developed for lack of a better word). Any help, opinions, or suggestions is greatly appreciated.

Thank you!!

Well they look healthy over all, truley they look like they are just hungrey, mabe lil bit of a nitrogen def, when you switched on to flower did u loose alot of nitrogen lvls in your feed scheduled??? if so add lil bit for next week and ween them off if that helps.

That curling looks normal, if you top it does that with the new leaf that returns sometimes, id only worry if a old leaf does that, that looks farley new to me.

Over all lot of room to work with man : )

 

[Danner]

I think I lost a little maybe but not too much. I just had a conversation with a friend about it and he brought to my attention that it may be because how I was feeding them in vegge. I wasn't flushing the system at all and was topping off with nutes to keep ppm level steady instead of adding back just water. He said that causes the nutrient solution to get out of balance and the plants may have gotten used to that, so now that they got fresh nutes they're not liking that possibly.

 

[Jimmycricket]

PH problem, and they want more N.

 

[Danner]

Okay, if it's a PH problem should I lower or raise the PH? And what about the nitrogen? How should I add and how much? Like I said, I'm using floranova grow and bloom, which both have nitrogen, so what else should I add to the mix?

 

[jlt1202]

You mite not have to add anything new you might just want to EITHER, feed more often, or give them more nute per feed and if your dwc you should be changing the water at least every week so it doesnt get old and stagnet. PH should be from 6-6.5 for good range lil high lil lower wont kill it but it grows the best in that range.

And idk what your friend was saying feeding in veg is how your supost to do it... dont know if im confused on what he said or if he is flat out confused

 

[Danner]

Well I guess it means this, plants don't use an equal amount of minerals that are in a nutrient solution. If I start off with a fresh batch of nutrient solution, there's the beginning ratio of elements in that solution. Since plants don't use an equal amount of nutrients, meaning they may use say more nitrogen than potassium for example, then when I add back nutrient solution to the res, the ratio is not going to be the same as when I started because the plant had used more of the nitrogen than potassium, making the nitrogen-to-potassium ratio unbalanced or different from the beginning ratio and leaving an excess amount of potassium in the solution. By draining the res and just starting from scratch with fresh nutrients gives you the same starting ratio of elements. Not draining the res and just adding more nutrient solution gives you a different ratio of elements. Does that make sense? Not sure if I explained that right, but it's what my friends point was.

I obviously don't know what the problem is since I'm on here asking though, but there's definitely a problem. The only reason I said I thought it was a PH problem is because the issues I had with my meters. Based on everything I've read about PH for hydro I've found the consensus to be anywhere from 5.0 - 6.0, with some stating levels up to 6.5 as being ok. I'd say the vast majority of things I've read indicate a PH of 5.7-5.9 as being optimal. But shit, I just read an article saying the optimal level is 5.2 for the entire grow, so who the hell knows really?? I find the more I read about something, the more confused I get because of a million different opinions.

Anyway, I appreciate the responses and if anyone else out there has a suggestion, I'd like to hear it.

Thanks!

 

[Jimmycricket]

twisted leaves is a PH thing. I dont know if you need to lower or raise it you gotta check the PH to see. a range of 5.3-5.9 is good for hydro a little higher is fine mostly.

as for getting more nitrogen, add whichever nute has the most nitrogen relative to the phosphorous and potassium.

 

[jlt1202]

Well I guess it means this, plants don't use an equal amount of minerals that are in a nutrient solution. If I start off with a fresh batch of nutrient solution, there's the beginning ratio of elements in that solution. Since plants don't use an equal amount of nutrients, meaning they may use say more nitrogen than potassium for example, then when I add back nutrient solution to the res, the ratio is not going to be the same as when I started because the plant had used more of the nitrogen than potassium, making the nitrogen-to-potassium ratio unbalanced or different from the beginning ratio and leaving an excess amount of potassium in the solution. By draining the res and just starting from scratch with fresh nutrients gives you the same starting ratio of elements. Not draining the res and just adding more nutrient solution gives you a different ratio of elements. Does that make sense? Not sure if I explained that right, but it's what my friends point was.

I obviously don't know what the problem is since I'm on here asking though, but there's definitely a problem. The only reason I said I thought it was a PH problem is because the issues I had with my meters. Based on everything I've read about PH for hydro I've found the consensus to be anywhere from 5.0 - 6.0, with some stating levels up to 6.5 as being ok. I'd say the vast majority of things I've read indicate a PH of 5.7-5.9 as being optimal. But shit, I just read an article saying the optimal level is 5.2 for the entire grow, so who the hell knows really?? I find the more I read about something, the more confused I get because of a million different opinions.

Anyway, I appreciate the responses and if anyone else out there has a suggestion, I'd like to hear it.

Thanks!

ok im geting what your saying, u were just adding more nutes every week to the same bucket of solution and geting a nute overload because the plant wasnt using enough of the nute.

Like you said if you flush (they say every 3-5 days) about every week you could get away with flushing it and adding more nutes couple days after you flush.

I have a aero bucket for cloning and i get clones out in 8 days and all i do is add water/root excelorator day 4 and i have no problems, i always wipe the container clean after every refill tho because it will build up grim and stuff you dont want : P

 

[maselsy]

Do not add Nitrogen. The photos you have of the leaf tips dropping downward is a clear sign of nitrogen toxicity, known as "The Claw".

I found this thread because I too am dealing with the same problem. It started with "The Claw", I flushed, and they straightened out. But now they are twisting, "tacoing" (cuffed margins), and are getting necrotic spots either on tips of leaf margins or interveinally at leaf tips. This is also only an issue on a couple of the plants, not all..

I believe my soil is around 6.4, which is too acidic and I am trying to correct it. So, pH could definitely be the culprit. Let me know if you find/found a solution!

EDIT: After doing some more research, it seems that I (and possibly you, too) am/are dealing with an acidic pH and magnesium deficiency. Mg uptake becomes drastically reduced at a (soil) pH below 6.5 (while N is still readily available). The cupping and twisting of leaves are the beginning signs of Mg def., followed by necrotic and chlorotic spotting at leaf tips, margins, and/or interveinally. Twisting is also indicative of pH imbalance.

 

[Logfram14]

Do not add Nitrogen. The photos you have of the leaf tips dropping downward is a clear sign of nitrogen toxicity, known as "The Claw".

I found this thread because I too am dealing with the same problem. It started with "The Claw", I flushed, and they straightened out. But now they are twisting, "tacoing" (cuffed margins), and are getting necrotic spots either on tips of leaf margins or interveinally at leaf tips. This is also only an issue on a couple of the plants, not all..

I believe my soil is around 6.4, which is too acidic and I am trying to correct it. So, pH could definitely be the culprit. Let me know if you find/found a solution!

EDIT: After doing some more research, it seems that I (and possibly you, too) am/are dealing with an acidic pH and magnesium deficiency. Mg uptake becomes drastically reduced at a (soil) pH below 6.5 (while N is still readily available). The cupping and twisting of leaves are the beginning signs of Mg def., followed by necrotic and chlorotic spotting at leaf tips, margins, and/or interveinally. Twisting is also indicative of pH imbalance.

Thank you, this answer helped me!!