minor problems, coco, let me know what you think

about 3 weeks old seedlings, growing in coco-perlite (50-50), been getting RO water with about 0.8EC (400 ppm at 0.5 conversion) of feeding with HESI TNT & Coco (about 50-50), root complex, powerzyme, GHE's Diamond Nectar and some epsom salt here and there.

I know they look ok but I am having problems they are just very minor, but I want to stop them.

Anybody have an idea on what I should do?
Flushing doesn't seem to help much.

Too many nutes? They're only 3 weeks old...
I'm not too familiar with hydro EC/ppm stuff, but I gave some half strength nutes to my seedlings at ~2 weeks and the bottom leaves went yellow almost identically to yours.
Took a while to recover, as it is then hard to tell if they need more nutes or if they're deficient...
Maybe just try keep it simple then add the specialty additives once they're looking healthy.

hows the root system doing? If you try and slide the plant/soil out can you see roots on the outside starting to loop around the cup? Do you have holes drilled in the bottom of the cup? Coco+Perlite doesn't hold water very well, and doesn't have any nutrients, IMHO you are underwatering and undernuting, and those cups are getting small

oh also what is the PH of your water+nutrients, it should be as close to 5.8 as you can get it

hey thanks for the replies:
answers - most plants have got a nice rootball already, poking out from below. The reason i'm holding back transplant to 3gl pots is due to lack of space for everyone (will be solved shortly). In the meantime I like being able to water more often with the cups, esp with problems going on. Do you think I should hurry to repot? I will try giving more waterings for the more mature plants.

pH is indeed a problem, no matter how much I flush them with acid water / nutrients it won't go below 6.2. Any tips?

pH is indeed a problem, no matter how much I flush them with acid water / nutrients it won't go below 6.2. Any tips?

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In my opinion 6.2 is perfect for soil. What type of lights you using atm? How close are they to the plants? Do you foliar spray them? If so, when do you do it?

HiIGrow said:

In my opinion 6.2 is perfect for soil. What type of lights you using atm? How close are they to the plants? Do you foliar spray them? If so, when do you do it?

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thanks!
it's not soil though, it's coco. closer to hydro than to soil.

I'm using 400w HPS atm 40-50cm away. I've foliar sprayed individual plants, none have received it more than once, with EC 0.25.

Regardless, its a solid medium. hydro requires different PH levels. I use 3 26w CFL's for seedlings. They grow for a month uder them. You want to foilar spray them just before they go lights out. The nutes in the water will leave burn dots on your plant under the light. Water acts like a magnifying glass on top of the leaves.

asaph said:

hey thanks for the replies:
answers - most plants have got a nice rootball already, poking out from below. The reason i'm holding back transplant to 3gl pots is due to lack of space for everyone (will be solved shortly). In the meantime I like being able to water more often with the cups, esp with problems going on. Do you think I should hurry to repot? I will try giving more waterings for the more mature plants.

pH is indeed a problem, no matter how much I flush them with acid water / nutrients it won't go below 6.2. Any tips?

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So you've got a nice root structure...transplant! It is time...your roots need more space at this point. Start upping your nutrients...you are not getting burn...if you notice the tips starting to yellow and die then dial it back a bit, but I think at this point you just need more nutrients

To get your PH down to 5.8 buy some ph down...its sold in pet stores across the globe for fish tanks

massah said:

So you've got a nice root structure...transplant! It is time...your roots need more space at this point. Start upping your nutrients...you are not getting burn...if you notice the tips starting to yellow and die then dial it back a bit, but I think at this point you just need more nutrients

To get your PH down to 5.8 buy some ph down...its sold in pet stores across the globe for fish tanks

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good advice thank you. I shall begin procedures for transplanting.

I do have the pH down - what I meant was that no matter that I feed with pH 5.8 or below, and even flush with it, the runoff won't go below 6.2.

asaph said:

good advice thank you. I shall begin procedures for transplanting.

I do have the pH down - what I meant was that no matter that I feed with pH 5.8 or below, and even flush with it, the runoff won't go below 6.2.

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Coco yes its a soiless medium, and yes i was wrong on the 5.8 PH for it...it seems most people go with about 6.0-6.2, so you should be fine there...if you want to bring the PH of your coco down just flush it with PH'ed water at like 5.5 and run it through it...coco takes changes to PH pretty well and will go lower if you flush it lower, but definitely transplant at this point

HiIGrow said:

Regardless, its a solid medium. hydro requires different PH levels. I use 3 26w CFL's for seedlings. They grow for a month uder them. You want to foilar spray them just before they go lights out. The nutes in the water will leave burn dots on your plant under the light. Water acts like a magnifying glass on top of the leaves.

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thanks. you should be informed - hydroton and rockwool also solid but you don't call growing in them soil. Coco may look like soil but that's about as much as it has to do with it - otherwise it's much more like rockwool.

I'll give them a foliar tomorrow morning before lights out. Can't hurt can it?

I don't like vegging with CFL's because I always get stretching.

massah said:

Coco yes its a soiless medium, and yes i was wrong on the 5.8 PH for it...it seems most people go with about 6.0-6.2, so you should be fine there...if you want to bring the PH of your coco down just flush it with PH'ed water at like 5.5 and run it through it...coco takes changes to PH pretty well and will go lower if you flush it lower, but definitely transplant at this point

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some people do go for 6.2 and even above and get good results. but most 'scientists' will recommend 5.6-6.0. They also say it depends on how you treat it - like soil or like hydro. Me I have no idea.

But get the funny part - I fill a smart pot with 3gl of coco, right? right out of the bag. I prepare a 3gl bucket with just RO water in it to wash the new pot. I pH it down to about 4! (shiny red in the liquid tester). Then I flush the pot with the whole 3gl of water. Runoff EC goes down from 1200 to 500. pH - stays 6.5, won't budge a bloody .1!

Is my coco totally fucked up? Why is it acting like that?

I run 5.8 for my coco. That is also what most coco growers recommend.

johny1212 said:

I run 5.8 for my coco. That is also what most coco growers recommend.

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when you take your coco from the bag, and run some RO water through it, what pH would you get in the runoff?

bump. anyone ever encountered coco that won't be ph downed?

"I fill a smart pot with 3gl of coco, right? right out of the bag. I prepare a 3gl bucket with just RO water in it to wash the new pot. I pH it down to about 4! (shiny red in the liquid tester). Then I flush the pot with the whole 3gl of water. Runoff EC goes down from 1200 to 500. pH - stays 6.5, won't budge a bloody .1!"