Yellow intervienal problem

Hi, I`m growing the cheese strain and having some problems I cant seem to get on top of. My last grow was down 2/3rds in yield and it looks like the same problem is occuring again.

I`ll add a couple of pictures to see if anyone here can see where I`m going wrong.

I`ve treated with epsom salts at 2 teaspoons per gallon thinking its a magnesium deficiency but it doesn`t seem to be helping here. Having said that I took a couple of cuttings from the same plants for a friend and they had the same problem, but epsom salts and strict control of ph (it goes up constantly and needs a lot of adjusting to keep down) seems to have gotten rid of the problem and they are looking very well now, being grown in the screen of green method. They`ve filled the net up and now budding like crazy.

They`re a few weeks ahead of mine and I want to try and get mine back on track.

I`m having the same problem with fast rising ph values, but keeping on top of that. The same nutrients (Cana Coco) and medium (Cana Coco mixed with 30%clay pebbles) are being used in both grows, I just cant figure it out.

My grow before last came in a little low without really doing anything about the yellow intervienal discolouring, and then my last grow was lousey and as stated above was a good 2/3rds down on normal, they just never filled out. I did get a bit sloppy during that grow and the cf and ph readings got out of hand for a while, stupidly I let myself get distarcted. I know of other growers growing from the same stock that have had bumper grows, so what the hell am I doing wrong. I`ve come across a lot of different problems in the past but never this one.

Please help if you can, thanks guys

don't be offended by any of this - I am just going to break it down real quick:

a) Looks like the ph is much lower than you think like in the high 4s - you really should not need ph correctors with chem nutes unless your tap water is >.4ms.

b) You should not need epsom salts with a balanced chem nutrient such as canna.

c) I have a feeling you are hyperfocusing on ph too much. First, if you are handwatering, how are you even measuring ph?

d) Remember if you handwater, your ph is going to drop as the water depletes. - what ph is your nutrient at 1.4 ec? Prob 6.0 - perfect for your needs.

e) If that is an ebb and flow system - most of this applies equally. I can elaborate if that is the case.

But basically, if you are handwatering, flush with plain water (runoff a gallon or so). Then immediately follow up with a nute solution with no ph down. That will get them growing again.

csharper said:

don't be offended by any of this - I am just going to break it down real quick:

a) Looks like the ph is much lower than you think like in the high 4s - you really should not need ph correctors with chem nutes unless your tap water is >.4ms.

b) You should not need epsom salts with a balanced chem nutrient such as canna.

c) I have a feeling you are hyperfocusing on ph too much. First, if you are handwatering, how are you even measuring ph?

d) Remember if you handwater, your ph is going to drop as the water depletes. - what ph is your nutrient at 1.4 ec? Prob 6.0 - perfect for your needs.

e) If that is an ebb and flow system - most of this applies equally. I can elaborate if that is the case.

But basically, if you are handwatering, flush with plain water (runoff a gallon or so). Then immediately follow up with a nute solution with no ph down. That will get them growing again.

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Thanks, but my ph meter checks out to be good with buffer 7. Its a recirculating hydro system with a dripper into each pot. I`m measuring the ph value each day and it rises from 5.4 tp 5.8 in a day and continues to rise if I dont correct it.

I have a couple elsewhere that had the same problem, but a couple of doses of epsom salts and strict ph control seem to have eradicated the problem, and there is no more yellowing in the leaves. They`re also a few weeks ahead of these at the end of week 4 (of 9) after quite a long veg peiod as its a scrog grow, mine are still in veg, was thinking of scroging these but I`ve now decided to grow them as normal plants. I`d usually switch em over around now but would like to get on top of this problem first rather than carry it into flowering. These other two have the same set up except there is one plant per tank in a 1.2x1.2x2 meter grow tent, and I`m using the same medium and nutes along with the same nutrient and ph meters in both set ups. These I`m showing here are 5 pots per tank (bigger tanks of course. I`ve been doing this for some time and a refugee of Operation Overgrow, so I`m no beginner, though I feel like it at the moment.

Thanks

Well, if you are saying you are doing everything the same as you have always done it and only now are you having this problem then I can't help you. Differences in strain wouldn't really matter. But if you recently changed medium or nutes - canna coco has not always been so popular, then your experience with other methods does not matter so much.

Two indisputable facts:
your canna nutrients suck if they *require* extra mg...
your canna nutrients suck if they require ph control - or you are using them too weak - or your water is >.4 ec itself

micro adjusting ph with ph down from 5.8 to 5.4 is ridiculous. Just let it rise to 6.2 or whatever and leave it or add more nutes as ph control. That is exactly what I meant by hyperfocusing on ph, and basically you are telling me that every day you add a few MLs of ph down. That builds up and plus 5.4 in the tank is probably 4.5 in the pots unless you have your drip frequency perfectly dialed in or figured out a way to drip extra without root rot. Also I am unsure why you need to force <6 in drip fed coco anyway..... your target is too low. Then there is the issue of where is all that extra P going.

You are actually trying to fight your nutrient's own buffers right now. That's why you can add ph down every day and it will make no long term difference until you overdo it, like now. I wrote about this here: http://www.icmag.com/ic/showpost.php?p=2604457&postcount=12 and you can read the water chemistry thread I linked there/from the hydro forum for even more info.

Seriously - even owning a digital meter is kinda pointless for hydroponics (considering the pain of storage and calibration). If you are having to adjust your ph more than once a month, if that, you are doing something wrong. And with a ph that stable all you need is a liquid drop kit. Or just trust your ec meter and your nutes - you should be able to.

I *never* use ph down anymore after I had the same problem you have in an old shallow water culture system - just use gh 0:2:3 to 1.5-1.8 ec and your ph will be perfect for your needs, unless your water is really bad... (note to newbies, not tokesome: you can use .9 for your seedlings and forget about the high ph for two weeks and be fine)

Keep going as you are and you will have iron/zinc def in the week. You are not going to want to use GH, but just use the same ec with canna. What ph is that solution? I guarantee it will stay the same ph at the same ec - there is something you can rely on. So as long as your plants dont eat it all, you got perfect ph - if they do, great, just add more nutes. If canna just cannot hold ph by itself in your res, lose the additives or that nutrient just sucks.

The idea of optimizing nutrient usage at a "perfect" PH or using a "range" of ph is over complication, and assumes that you have more light than you need and everything else in the environment dialed in perfectly, and I mean perfect. Otherwise you are overcompensating for your loss/lack of control in other areas by overcontrolling ph.

edit: even then you would have to know the exact mathematics, chemistry and per compund breakdown of your res. Otherwise, you are just perpetually experimenting.

The Ask Lucas thread can give you a thorough explanation of this simple school of growing.

5.4 is a bit low for coco, 5.8 to 6.2 is fine ..... @ 5.4 you may be locking up the N, 'cos it sure look like N deficiency is major part of that yellowing

Otherwise csharper has you covered

BD

Well times and ideas change. I`ve always gone for a ph of between 5.2 and 6.2, usually aiming for 5.6 to 5.8. My nutes for veg never exceeds 1.2EC and usually around 0.9, during flowering when they require more I`ll let it go up to 1.8EC if they`ll drink it, but more usually 1.6EC. If I give them more than that the nutrient concentration gets higher. The last grow where I admittedly got a bit sloppy I found the EC had risen to high 3`s.

I dont think my plants should be suffering due to too low a nutrient strength or the ph regime, but I`ll try what you say and see what happens. I dont understand why these other 2 are doing ok now, but still having problems here.

Yes I`ve heard a lot of bad stuff about Canna nutes, but have used them with good results (4.4oz a plant, without training or scrogging) for a long time now, but again here I`m not opposed to trying something different. The only addatives I use are superthrive in small quantities throughtout the grow and PK13/14 for a week 3 weeks before harvest.

I`ve just re filled the tanks and have them at 0.9EC and ph at 5.7. I`ll see what happens as it rises without adjusting and come back with results.

Thanks for your advice, I appreciate the time and effort. Do you really manage without a ph meter for all your growing?

I had a ph meter while I was handwatering coco and during that swc coco run. For handwatering with runoff which is drain to waste - it won't kill anything to adjust ph. It isn't needed, but there won't be ph down buildup cause of the runoff. But when I almost killed my swc doing the same thing you were doing, much to the same result as your pics, that is when I read and researched the concepts in the ask lucas thread.

For my last two, and only ebb and flow grows, I have not even changed the res and maybe checked ph once or twice just for the heck of it. Only using a gh liquid kit and all you look for is orange-yellow coloring. If you see green tint, up the nutes until its yellow, red your nutes are too strong or your ratios are way off.

All of this is covered in the first 20 pages of the ask lucas thread and I am just summarizing it based on my positive experiences.

I could write another essay on why you have different results - but I'll just put the questions in your head - can you tell me there is absolutely no other difference between your grow and the other healthy setup other than plant count, stage of growth, and that the time that the problem set in? But just think about how those three variables effect your res - of course there will be differences. Do you take notes on the amount of ph down added or just add it til you get to your target? If you did take notes, you would wonder why you have to add 3ml one day, 2 mls the next, 5 the next and so on. Even depending on the amount you add at a time vs what was already in the res you could have different reactions. Were you doing res changes on a fixed schedule, etc. etc. I wouldn't worry about all that too, too much - because IMO all you need to know is that there is potential for something to go wrong earlier on. LOL - this is why you want to keep it as simple as possible - otherwise you have to go to school for chem/bio/and math and even then, humans don't understand close to everything yet.

Back to the main problem:

Can you tell me how much water volume you are dripping through what volume pots daily? Also what is the pump schedule. I want to say you need more than .9 ec as I know that wouldn't hold ph with my .05 ec tap water, and I doubt it will for you either. But I also don't want you to burn your plants if the drip frequency is too low. But please don't add ph down to this res - safely. But then again, I once daily handwatered coco in 1 gal pots to a very nice harvest at 1.4 ec through flower. So I pretty much know you can go that high at least which would actually be enough.

If you feel you need to do something before a response (like if .9 ends up at 6.8 or something), 1.2 is the logical compromise since you are in a conservative mindset. You will notice your ph go down right away. Note you prob have acid buildup in your pots so high ph today isn't going to kill anything. Phosphate will get washed into the res faster than most other nutes so you will know today what effect if any residual has. The residue should not be significant enough to make you change your res again as your plants would be dead if there was that much.

Also real quick, something to think about: You could say your nutes are balanced if your ec does not rise at all as your water depletes. But if your pot is not fully saturated all the time, like drip, ebbflow and handwater, and the nutes are slightly "overbalanced" to the water, then as the water is used but only some of the nutes it is going to naturally make a higher ec/lower ph in the pots and do the whole ph ranging thing that everybody tries to duplicate manually. That is more something to keep in mind, than try to engineer a ph sway today. I would just shoot for stable 5.8-6.2 and you will be golden.

Problems or questions, I'll be checking in....

btw, no res changes is potentially complicating things - and you could prob get away with some amount less ec to the same ph if you didn't have to buffer out residuals. Plus you want to find a formula that others testify will work perpetually - don't know about the canna ratios.

edit for public: but that doesn't mean canna can't work, just have to do your own research

looks like n deficiency to me probably due to to much ph down. i very rarely have to use ph down with canna coco and canna nutes just set your ec to 1.2 - 1.6 and ph should correct itself
you canna beat canna

Canna nutes were the best, as you say though things move on, I've tried loads and spent a fortune on some (BAC and AN for instance), now in coco I use Hesi and start Vitalink Buddy at day 7 flower instead of P/K 13/14, as I find the coco makes the additional K in Buddy a real bonus inducing flowering and increasing the final yield

My 600w always gives over 1g/w and that's using Hesi with molasses

Don't follow their feed schedule, there's too much N in the Bloom, taper it off to 1ml/l after 5 weeks then stop giving Bloom feed

Hi, thanks for chipping in guys.

csharper, I dont know the volumes of my drip system. In fact its not really a dripper exactly as I use them without the drip nodes in them so it just pumps a constant flow from the res set to come on for 45mins 4 times during the feed cycle. This sounds a lot but the drainage is good with the bottom 2 inches being clay pebbles and the coco also has a 30% mix of clay pebbles in it.

I cant say there is no difference at all between the set ups here and with the other 2 I`ve mentioned, but any differences are very small and they`re acting the same in regards to ph values etc. These other 2 are a few weeks advance on the others but had the same problem. I treated with epsom salts and ph`d as I`ve stated and they`ve fully recovered and look A1, I`ll try and take some pics tmro and post them. There are no yellowing leaves and they`re budding up very nicely.

This strain has suffered from this problem for the last two grows, 1st significant intervienal yellowing but still produced a decent yield, the 2nd just didn`t fill out at all in the final 3 weeks and was during high temps outside which I know didn`t help. I grow all year round and recognise the differences that the season may bring with summer peak temps being the worse, but never anything like as bad as this last grow.

My plants are producing shoots and leaves and are responding to nipping out the tops as I`d expect, though maybe a little slower than usual. The nute strength remains constant throughout the week (thats how often I completely change the res.).

Its great to have some support here, in particular thanks to csharper, but also to you other guys

Mmm. . . .csharper, you were right from the off, thanks for pointing me in the right direction. I checked my ph meter in ph buffer 7 and it was reading 7.5, meaning that when I was forcing it down to 5.2/5.4 it was really going down to 4.7/4.9 which expains things. It must`ve been longer than I thought since I checked the meter, but I really thought I`d done it fairly recently. My last plants suffered the same and the ones before that(but not so badly) and I definitely checked it during the last grow.

Its still puzzling the arse off me why the other 2 have recovered from this problem and appear to be doing very well, sorry, still no pics but I should be able to get some over the weekend.

Attached here are a couple of pics from my last grow near to a very poor harvest. one of a couple of leaves and one of the very sad tops. The yellow intervienal discolouring had been present throughout the grow, it didn`t kill em, but seriously affected the yield.

Thanks again, you may have saved my bacon, or er. . . my cheese

Do you think extending their veg time would give them more chance of recovery, or do you think they`ll pick up if I switch em to 12/12 now? They`re about the height I`d switch em at, but will train em for a while if it`ll give them a better start into flowering.

Hi Tokesome,
I'm not real familiar with Lucas's way of thinking, but I found csharpers info interesting. Glad you found the source of your ph error. I'd recommend getting some narrow range litmus paper. It's a little more conveneint then the drop system. I use it to double check my ph meter or sometimes just alone.

On the flowering now question...I'd personally wait till they're recovered before submitting them to the stress of induced flowering. Good luck...
ET

EvilTwin said:

On the flowering now question...I'd personally wait till they're recovered before submitting them to the stress of induced flowering. Good luck...

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I agree

What about my feeding regime guys. I have the timer set to 4x45 minute feeds, no dripper nodes on the end of the pipes feeding each pot, so there is a good flush through run off each feed. I have suffered root rot once before, but this was down to me not having any clay pebbles in the mix and no layer of pebbles at the bottom of each pot,

Do you think that`s about right. I`m going to flush my plants for 24 hours with ph 6 water. Then give them a nicely mixed nutrient. I`m hoping I haven`t caused problems that will be difficult to rectify, are there any tips or concerns that you have for my set-up that would help ensure the good health of my plants, and thus a good harvest.

Thanks guys

Tokesome, I don't know what the manufacturer of your meter recommends, but using buffer 7 is like using a penny to calibrate your 500g scales -- my milwaukee recommended something like 4.0 or 10.0 depending on which side you were going to be working with. So in my understanding, calibrating your meter to 7.0 is not really testing the ph "signal" reading - kinda like if you test a radio tower by making sure it is static at the maximum transmission distance (0 signal point) - but not actually testing your radio in range.

Tokesome - the more you can feed without root rot the better - as that allows you to use a higher ec to solve your original (ph) problem as the pots are NOT drying between waterings shooting the ec up (in the pot) even higher.

PLEASE don't flush your plants with regular water - I can't go into details, but from reading basic botany sources, I know there is an opposite condition (too weak) from nutrient burn (too strong), where the plants can not get any nutes out of the water or actually start having stuff pulled out of them into the water. Search for turgidity and root osmosis if you want to learn more.

Why are you doing that - I thought you were going to work for a stable ec/ph res?

Bush Dr said:

5.4 is a bit low for coco, 5.8 to 6.2 is fine ..... @ 5.4 you may be locking up the N, 'cos it sure look like N deficiency is major part of that yellowing

Otherwise csharper has you covered

BD

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Agreed looks like N

Surely to test your meter`s callibration it`d be closer to where we`re using them hence buffer 7 as sold in most grow shops. I`m going to get a colour ph test kit and keep back up readings with it to be on the safe side.

I dont understand either, why not to flush through with plain ph balanced water, its widely recommended as a standard exercise. Or have things totally moved on since I was last tapping the keys of my computer to access info on this subject?

My ph had dropped to 5.6 and 5.7 and nutrient strength has risen to 11-13.

I`ll give fresh tanks of ph 5.8-6.0 with ec around 1.2. I suspect though that the Ec level will rise as the tank is used up.

I find what you say very interesting and you obviously think very hard to understand this whole thing, and I really appreciate it mate, but I find it difficult to understand some of what you say and some of it goes totally against what I`ve learnt and practiced. Please dont be offended by that though, I like my brain and thinking to be questioned and challenged, many thanks again.