15 plant coco grow, recurring Nutrient/Magnesium deficiency problem

[Tokesome]

I`m going to experiment with feed times and intervals, all on the reduced side of things.

I dont know if my plants are just slowed down as a result of their suffering, or whether too much water/feed is the cause of the problem. The two plants I have that are going well are in the same 3 gallon pots, although one difference I`ve realised between these 2 and my others is that they had an inbetween potting up stage from plastic cups to 5ltr pots before going to their final 5gallon pots, so they wouldn`t have taken so long for the roots to colonise the 3 gall pots and maybe got cooking quicker. My friends are growing the same strain in coco in auto feed pots with no such issues, feeding twice a day until run off.

I`m hoping that switching to RO water and keeping a close eye on the moisture hold/loss of the medium will cover my issues.

Just wondering Tip, why such small pots, you sog growing these ones? Also what wire mesh are you using? I`m wondering about the safety of using anything that could add to the nutrient balance in the root zone, ie. from rusting or other elements such as zinc. I like the idea very much in principle, can you feed more now without problems now?

Toke

 

[tip302327]

I grow short crop clones 2 weeks to 2 days veg time depending because I grow in a vert 3 tier circ garden, perpetual. The shelves are only 30" apart so I cant handle long veg times and always figured if it isnt in the flower room it isnt growing bud. Since my patients dont smoke leaf....well, you get it. The mesh is galvanized, 1/4 weave. I ment to take a pic of the bottom of the pots to show root growth. I set the pots on 1/2" wood strips in order to assist draining and to let the air go to all 6 sides. So far the only drawback I can find is that they are messy if you have to handle them for the first 2 weeks, and the wire sticks you every so often. Other than that, after 8 weeks of use I think they are superior to anything available, or in this case not. A perfect pot would mimic this design but in plastic. Not tuting my horn either. For COCO, they work excellent.

My personal opinion... RO water will not fix your problem. I spent a year in coco with well water at 23 ppm. My take...it's a weed. It will grow despite you. Get rid of the wet bottom in coco and be happy. So far that has been my case. Again, just my opinion. MJ does not like wet feet. If you are in balance with PH, air, ppm, Rh, light and temp it will grow well so I look for the common denom when I have some plants not doing as well as others in the same grow. If your plants down the street are doing well....water is not the issue. Last time...just my opinion. t

 

[Tokesome]

My personal opinion... RO water will not fix your problem. I spent a year in coco with well water at 23 ppm. My take...it's a weed. It will grow despite you. Get rid of the wet bottom in coco and be happy. So far that has been my case. Again, just my opinion. MJ does not like wet feet. If you are in balance with PH, air, ppm, Rh, light and temp it will grow well so I look for the common denom when I have some plants not doing as well as others in the same grow. If your plants down the street are doing well....water is not the issue. Last time...just my opinion. t

Maybe very wise mate, but I`ve been growing in coco for many years without this issue, and watered to keep the pots always moist to wet. I`ve found here at ICmag that some people have issues with wet feet and some dont. I mean you`ll find threads here where people feed 2-3 times a day until run off and some that let them dry out more because of issues with wet feet and fungas gnats etc. Perhaps its strain specific where some may love it wet and some may not cope so well in coco. I came from Hydro where things are often consantly wet, different uptake of oxygen though of course.

I`m going to try and feed one tank, 1&1/2 pints per plant per day ( until their demands go up as the plant grows). One tank I`ll feed daily until run off starts, and the other tank I`ll feed till run off once every 3 days ( unless the pots become light in the mean time).

Its the simplest of tests and will defo show if the feeding regime is responsible for my problems. I`ll fit the RO filter, at least I`ll know what they`re getting is the correct balance of uptakeable nutrients, once I establish it with a mix of RO/tap water or all RO with the correct added macro ellements. It sounds a bit complicated I accept, but its simple science really. I drink far more water when I drink bottled water in comparison with tap water, so at least my own system will benefit from drinking more water.

I`d like to think that its just as simple as wet feet, despite the fact that I`d be down on myself if its been this all along, as it`d be the easiest thing to correct, It seems like it must be something pretty fundemental, but I suspect there is more going on, we`ll soon see eh?

Not so sure about galvanised, especially in a recirculating set up like mine, but I like the idea of mesh pots, I wonder if they can be made up with plastic mesh and lots of zip ties? Maybe lined with a single sheet of nft/hydro spreader mat for a breathable lining?

Filter should be here this week, and hopefully the plants will begin to show the differences if any from the feeding regime changes by the beginning of next week.

Toke

 

[EvilTwin]

Mornin' T,
I don't remember if you and I discussed the different grinds of coco. A buddy of mine had no end of problems with a super-fine grind. GH came out with a very coarse coco more for hydro use called "natural mixed brick". It's very well draining. I haven't actually tried growing a plant in it...but I expect it to work very well.

Someone mentioned on a thread somewhere that Canna actually suggests more of a wet/dry schedule. I don't know if that was in reference to Canna nutes or coco. Something you might research in all your spare time. lol

I wouldn't use galvanised mesh with a recirculating system but if you Google air root pruning or air pots...that'll lead you to some plastic "air pots" with scalloped holes all around the sides. Idea is that the roots don't get locked into the circling thing that they do in regular pots.

They were developed your side of the pond...Scotland I believe. Here's a link...

http://www.cherrylake.com/Resources/RoomToGrow.pdf

Peace,
ET

 

[tip302327]

Morning all. I have heard of the super course coco but haven tried it yet. I certainly want to try it. The more I ponder this wet feet issue the more I believe that when using coco it is best to keep whatever container you are using short and wide. I use a 30 gallon plastic drum to pre wash and treat 1 large compressed coco brick. I drilled many holes in the bottom to let it drain. The barrel is maybe 30" x 18" I would guess. When I go to use the new preped coco the top 12" or so is perfect. Lite and fluffy. The futher down I get into the barrel the worse it gets. The last third being so compressed I have to use a pry bar to get it out of the barrel. The last third is also soaked with moisture. It doesent matter how long the tub drains either. It is doing the same in pots too. Allthough I have never grown in slabs or beds of coco, I can see where they might work better than deep pots. In my DIY 6x6x6 pots the coco is not deep enough to have these problems. They will finish a short crop with plants around 20" or less but not any bigger. For a 30" plant, which for me is perfect I think a pot 12x12x8 or 10 would be perfect. I agree, I didnt care for the galvi wire mesh but it was all that was available. Me being me, I have to go the DIY route, I am just to cheap...I am going to look into plastic dipping the pots but dont know if it will be cost effective.
On a side note, I have with rather good results, placed black scotch brite pads, cut to fit, from floor buffing pads in the bottom of regular plastic pots. It did drain much better but still leaves the problem that you are using up grow mediun to agument drainage. t

 

[EvilTwin]

Tip,
May I ask you a question. I'm not sure that I agree with you on the wet feet thing. It used to be that proper bottom drainage was considered crucial.

But these days, thinking has changed. First there's the hempy bucket with a built-in reservoir of nutrients at the bottom for the roots to sip from. Ebb and Gro systems are designed with incomplete drainage to provide a small nutrient reservor. DJ Short mentioned in his book that he doesn't recommend rocks on the bottom so that the plants have some nutrients to tap into.

I could come up with other examples but the point being that there seems to be a trend moving away from the "drainage as being crucial" school of thought.

You're a thoughful grower...what do you make of all that?
ET

 

[tip302327]

Indeed. As I have pondered and researched many of what you have mentioned above. Sometimes at a loss myself. It seems for every one opinion there is yet another. With so many variables in each room and in growers themselfs I dont think there is any one "right" way to grow. One thing the buckets, DWC etc offer is high leveles of dissolved oxy in solution. I suspect in a pot however that it takes little time for the plant to use it up. An interesting debate non the less. I wish I had some sort of intellegent explaination as to why all other things being equal, my plants in mesh pots just overall have more vigor and are greener than any others and lack that cal/mag def. look to the leafs. I can only put it to the way the pots drain and expose openly, all sides to fresh air. I can only say what I see. I cannot however, explain it...as silly as it does sound. The "wire" in the pots has nothing to do with it other than it uses such little space to hold the coco. All of this of course is simply, my opinion. Until I have grown for a period of time in these pots, it is all speculation. t

 

[EvilTwin]

Indeed. As I have pondered and researched many of what you have mentioned above. Sometimes at a loss myself. It seems for every one opinion there is yet another. With so many variables in each room and in growers themselfs I dont think there is any one "right" way to grow. One thing the buckets, DWC etc offer is high leveles of dissolved oxy in solution. I suspect in a pot however that it takes little time for the plant to use it up. An interesting debate non the less. I wish I had some sort of intellegent explaination as to why all other things being equal, my plants in mesh pots just overall have more vigor and are greener than any others and lack that cal/mag def. look to the leafs. I can only put it to the way the pots drain and expose openly, all sides to fresh air. I can only say what I see. I cannot however, explain it...as silly as it does sound. The "wire" in the pots has nothing to do with it other than it uses such little space to hold the coco. All of this of course is simply, my opinion. Until I have grown for a period of time in these pots, it is all speculation. t

It's a mystery to me too. The Hempy buckets...which I've used, seem like a sure fire recipe for root rot. Yet people grow monster plants.

I currently have about a dozen soil plants growing. All are fine except one which is showing...(drum roll) brown spots on the leaves. It's a White Widow x Cali Orange Bud cross I made a while back. Never was too impressed with the OB side and after this I'm abandoning all further work with that strain. All plants in the same soil with the same nutrients and water...only one plant has the problem.

I'll let you know if I figure out the cause.
ET

 

[Tokesome]

Well, the pots that I haven`t fed for 5 days are still moist and reasonably heavy, so I`m leaving them. I dont think I`ll go with the daily feed till run off for the time being.

I`m not so sure about this being my plants problems or a symptom of a deeper problem, its too early to say for sure but the problem seems to have arrested itself, its certainly isn`t increasing at the rate it was before and I`m keeping a careful eye on particular leaves to see if its still progressing. This is probably nothing to do with what I`m doing though, the same happened last grow, early signs of this problem cleared up and then came back later in the grow. Fuck, its so puzzling!

One thing that leads me to think it may be to be with the medium being too wet, is that these plants were potted up from 1/2 liter plastic cups straight up to 3 gall pots, therefore the pots are going to be very wet as the plants couldn`t possibly drink it up, being so small. I can see them then picking up as they build up a root system and more on top. It may have been the case last grow, and then maybe I got over ambitious with feeding as they got going in flower. I know the feeding regime I`ve been using suits at least some other strains without issue, but as I mentioned earlier this strain may not have good tolerance to low oxygenated medium.

If I cant get anywhere with this problem with careful feeding and using RO water, I`ll probably ditch and start fresh with something else. I dont like to think that way though when I can see them doing so well elsewhere.

Toke

 

[EvilTwin]

T,
That's a pretty dramatic up-potting. Roots don't have a chance to develop good. I'd put two up-pottings between those two sizes. But I really don't think that's related to your current issue.

It's part of the nature of growing to change and try new things. So if you do abandon coco...nobody can ever say you didn't give it a fair shot.

I gave up on small plant sog using hydroton in pots on 3x3 trays. Too much damn cloning. But nothing has produced for me with such ease as that system...so I may be going back to that...at least partially. I'd run the res for the whole grow till flush. Top up/add nutes and ph every two days and just generally neglect them. And juicy powerful White Widow buds were the end result.

Just bouncing around...a bit stoned,
ET

 

[tip302327]

In the end, what keeps me going forward, learning, is the fact that everytime I THINK that i have this figured out....I dont. t

 

[Tokesome]

Well on a brighter note, I`ve made some lovely Butane honey oil tonight

Hey ET, I`ve had a good look around the web but cant find anything to suggest that Canna are advising more of a wet dry cycle, do you know where you saw that info?

Yeah, I realise that`s to great a pot size jump jump, but they`re showing roots through the holes in the bottom of the pots and feel sturdy enough so hopefully ok there. Any thoughts on what is happening here ET? Too wet, maybe, not sure though, RO water, maybe, not sure though, anything else?

I`ve started some LST training today, I`d nipped the tops out a while back and now bending over and tying down the top two stems that branched from the nipping out.

If I get on top of this problem early enough I`ll remove all the affected leaves (the ones yellowed between the veins). This way I`ll be able to notice any future yellowing. Ooer, justy thinking, wishfully, out loud.

Toke

 

[Tokesome]

In the end, what keeps me going forward, learning, is the fact that everytime I THINK that i have this figured out....I dont. t

Man, do I hear that??

 

[PoopyTeaBags]

Your pH, at 5.2-5.4, is WAY too low for coco. Try it between 5.9 and 6.1 and watch the improvement.

5.2 is low 5.4-5.8 is what i keep mine at just like any other hydro medium
sometimes i let it drift alittle higher but never higher then 6.2

alot of people try and run it like soil... but its not

 

[Tokesome]

Other than the fading of colour between the veins there is a distinct lack of sheen to the leaves, dry looking and quite lime coloured. T

 

[Tokesome]

Oh I just love my spaced head on honey oil ;-)

 

[tip302327]

LOL, that my friend....gives little to solving the problem here. funny as it is though.

 

[cskis11]

My 2 cents

My 2 cents

Hi Toke and others, I have five years growing experience: the first two I used a peat-based medium (Promix HP) and the last three I have used coco. When I first switched over to coco I encountered many of the symptoms that have been brought up in this thread; I've scanned through most of it though I might have missed quite a bit, but hopefully you find some of the following information useful.

First my setup and methods:

I have separate rooms for veg and Bud. Clones are grown for three weeks in veg under 1 x 1000W metal halide and then switched to bud under 2 x 1000w HPS. They start off in beer cups for the first week and a half of veg and then I transplant them to 1gal containers where they spend the second half of veg. When they are transferred to bloom I transplant them again to 3gal pots.

The second stage, using 1gal pots, added an average of 0.5oz to each plant when I tested it against a set of plants that were transplanted straight from beer cups to 3gal pots. When I examined the root balls of the plants that had skipped the middle stage there was far less root formation in the middle areas of the pot. It seems when using the middle stage there is a much larger root system in place available to take up water much more quickly when I transfer them to 3 gal pots. I consider this a crucial stage now as I have read (and seen for myself) that roots propagate very quickly in coco, shooting out quickly in all directions, but not branching out to fill out inbetween space very much.

The main difference that I've noticed in how I do things versus your methods is that I only water / feed them once a week by hand, with about 25% runoff (usually 2gal of water per plant in bloom). I think this is relevant to your problem because whenever my Mg (and sometimes N def) problems arise they invariably occur within the first 48 hours of feeding, then over the next five days until they are watered again the plants seem to make a fairly vigorous recovery.

The other thing I must mention is that by the time they're in bloom I'm feeding them fairly heavy with each watering: 1400-1600ppm (EC 2.8 - 3.2). This seems really high in comparison to most numbers that I see people floating out there, but if I go lower than this the plants begin to show definite general nute def problems.

When I was using Promix I was growing about 12 plants per cycle and averaging around 2.2 Oz per plant. In coco the best I have averaged is 1.8 Oz per plant, but since I do not have to deal with disposing of soil each cycle I can grow 24 plants each time, which to me is the greatest benefit of Coco. I simply remove the root balls after each harvest and then top my supply off with another bag to cover the loss. I've been doing this for three years with no loss of quality or quantity in terms of final product.

Back to my Mg problem and how I solved it:

When I first encountered these problems some research led me to the same conclusion as many of you that some kind of Mg def or lockout was occurring. I read about the interplay between Ca and Mg and then after buying an EC meter (truncheon) discovered my tapwater was at around 150 ppm (EC 0.3). Since I was constantly dealing with calcium deposits on my humidifier hotplate I came to the conclusion that a large percentage of my tapwater EC reading was probably caused by Ca.

At the time I was using the GH FloraNova series (Grow and Bloom); each one has a set ratio of Ca vs Mg. Since I could not alter the ratio between these two nutrients I decided to look into a different system.

The one I settled on was a 3 part system by Grotek. In this series the Mg is isolated in the "Grow" and "Bloom" mixes, while the Ca is found in "Micro" mix. This gave me some control over their ratio. I performed a trial in which I gave 3 sets of plants differing amounts of the "micro" mix and found that my symptoms increased drastically if I exceeded a certain threshold of the "micro".

Once I established the correct ratios I never had any signs of Mg def again, except very occasionally (fluctuating tapwater content???). There are probably a lot of other factors at play (nutrient ratios etc.) but I have found my results from this three-part series to be far better overall in coco than FloraNova. (I also add a sugar / amino acid supplement "Bud Candy" and later in bloom "Monster Bloom")

However recently Grotek discontinued this line of nutrients and I was forced to switch to another brand and have since re-encountered these problems (that's how I ended up on this thread). I'm now thinking of using the General Hydroponics 3 part solution for my next batch. They offer two versions of their "micro" mix: the normal one with 5% Ca, and a specific hard water one with only 1% Ca. I'm going to perform some experiments with various mixes of the two.

Some Conclusions:

While I don't expect anyone to drastically alter their system based on what I've said, hopefully you can gain something from it. Consider some of the following:

1. Perform a trial with a plant or two using a more wet / dry method of watering then you have been. Try even letting a plant go a week between waterings.

2. Consider a nutrient system that allows you to manipulate your Ca / Mg ratio and perform some trials.

3. Consider adding a middle stage in terms of pot size.

4. When you see your symptoms starting to happen try giving your plants a "double night", by this I mean 36 hours of straight dark (skipping one light period.) This is something I discovered by accident a few years ago and seems to give the plants a tremendous boost regardless whether they are suffering from some kind of nute def or not. (I do this about once every two weeks when they're in bloom regardless).

5. Don't use MagCal or CalMax or anything like that. They will only increase your Ca to Mg ratio. (If hard water here is part have your problem.)

6. Looking through your pictures your plants exhibit some of the classic symptoms of over-watering: leaves that droop and bend downward, an overall glossy green look to the leaves (sorry I can't describe it better than that), an overall droopiness and lack of vigour.

If any of this helps or you have any questions just respond, I'll be checking this thread fairly frequently.

 

[tip302327]

I would agree totally. I have thought for some time that just MG would be the ticket. I would also agree that a good cycle of no water in coco is a plus. I know this for a fact but it seems to go against what the masses say. I also must mention that allthough I have never brought myself to feed the numbers you suggest I do believe it note worthly. I gave 3 plants a 1200 ppm feed a few days ago, roughly 300 more than I do on week 5 / 6 of 8. I expected some sort of burn to develop. None so far and the plants actually seem to like it. These were Lemon Kush plants. Oddly. All my broad leafs, with little care I might add are doing just fine. You mentioned shinney leafs. I have a batch of about 8 LK's that are just kicking ass. They almost look like a fake plant in that the leafs are a dark green, pitcure perfect and abnormally shiney. For week 7.5 I am suprised that the bud formation is so good as they appear to be heavy on N but I know this is not the case. Just another WTF! I still think/say that there is something to letting coco cycle, maybe not enough to jack ec/ppm but...t

 

[EvilTwin]

Hi Guys,
Interesting post Cski. I haven't hear much talk about a Ca/Mg ratio but it makes sense. There's much misunderstanding about deciciencies of those two. You even see people posting that they think they have a CaMg deficiency...as if the two were somehow linked and can't be considered seperately.

I don't mean to harp on this issue...but the wet/dry ussue is also very dependent on the grind of the coco. There's two ways to use coco. As a soil substitute using a wet/dry schedule. And as a hydro medium never allowing it to dry. Usually run-to-waste. You'll see many hydro style coco growers that understand this and since trying to find the correct coco can be a pain...they amend with perlite or hydroton. The best coco grows I've ever seen were top drip multiple feedings (to run-off) 3-4 times a day.

Tokesome...I probably shouldn't have mentioned that Canna thing. It was just something that someone posted here that stuck in my mind. I also tried to find info on that and failed. maybe an email to tech support at Canna.
ET