My Coco Retardation - Re-occuring Seedling Problem

Hi everyone!

Been lurking around rollitup for quite a long time now, love the community and all the knowledge on display! About six months ago I finally thought id gathered enough knowledge to begin my own indoor grows, and coco coir mixed with perlite made the most sense to me for the growing medium.

Last run was great with the Nirvana NL! Fast healthy new growth, tight internodes, could read the plant and feed accordingly and lst'ed very successfully which all in all yielded me over 2.5 zips from a 16inch tall bush. So all thats good except for...

The seedling stage! Every time a seed in my household touches coco it turns to crap. Each time I get to the point where the first two setts of true leaves have grown out...Then the stunting starts! Yellowing leaves, droopy unhappy looking leaves and no good growth for basically up to two weeks

Now I thought I got the hang of coco last run, but clearly didn't! I germinated 2 Arjans Haze #3 girls around 2 weeks ago, and have the same set of problems as last run. First real leaves appear which is always followed by rapid deterioration in color and vigor.
The enviromental factors are as follows....

-Light-400w hps, approx 1 foot from tops. Was running 24hours now running 20hours. (son-t globe, no cooltube)

-Exhaust- 8inch centrifugal grow-lush. Passive intakes, Carbon filter.

-Medium- 60% canna coco 40% perlite.

-Feed- For seedling H&G base nutes with Canna Rhizotonic. 2-4ml per litre of the rhizo. Feed every water, every 48 hours.

-PH- Ranging from 5.6-5.8 for the feed water, never tested medium, but flush with 5.8 water regardless of being canna coco so I think I'm safe there...

-EC- 0.3-0.4 from the beginning of the first true leaves, usually stepping up to 0.6-0.8 at second set then to 1.2 etc etc.

-Water- Tap water with an EC of ~0.1

-Temp and RH- ~70F lights on and 40% RH

Now the things I have tried so far (changing one variable at a time to try figure out my continuing problem) are: Move the light upwards to 16inch approx, water/feed less often, flushed, and after none of those helped at all, as of yesterday raised to EC to approx 1.0 (yes probably the wrong move )

I really hope someone can tell me how to improve what I'm doing, as I'm slightly OCD and losing all this time in the seedling stage is more time waiting to see my first gorgeous sativas in action

Anyway here are some pics (want closer shots etc, just ask!) of the two Haze ladies and I thought I'd throw in a pic of my NL clone as well which is well on its way to dank heaven. I included it because they all receive similar treatment/environment and I can see the haze girls ending up looking just as bad if I dont improve my game....




As you can see, they look bloody horrible! (even worse in natural sunlight so i found out!) I apoligise to them everyday lol...Im not too worried about the NL dying, just my little sativa babies ;p Thanks a ton for reading my long ass post, looking forward to chatting with you all!

Spent the last hour reading about light bleaching, although its existence seems to be highly debated? Anyhow, just went and measured the distance from globe to plants and it was actually around the 10" mark (not 12" like previously thought) but the canopy is as cool as a cucumber, as in cant feel radiating heat at all at canopy level....not that I know for sure thats the problem, but moved the light to about 14". Suppose it wont hurt anything, so why not try!

Mixing Perlite with coco does nothing. Coco provides excellent drainage and airation on its own. The problem is the coco. If you use coco you just about have to use coco specific nutes from day one. In a soil mix mag, cal and k issues are a near guarantee. Last one I tried coco mix on had issues all the way to flower therefore I am expecting it to produce very little.

I am using coco specific house & garden brand nutrients, and have always mixed the coco with perlite with good results (not saying its correct, im no expert) its just this damn seedling stage (first two weeks or so, which ends up being longer due to slow growth) I always have problems with, then the plants pick back up, regain color and grow like crazy. You think the perlite has something to do with this?

try raising the pH to 6.0 if that dont help i dont know what to tell you.

and also pH you solution right after adding nutrients then wait 12 hours and pH it again make sure your tap is not playing games with your pH. it can swing this is why i gave up on pH and started using Dol lime on everything.

Have you had success with coco amended with lime? Yet another subject that always seems to be debated... I will raise the ph to 6.0 and ill mix my nutes tonight for tomorrows feeding (I usually mix the bases one at a time, then additives, then ph, then let sit for only half an hour to test again and its always the same)

What specific nutrient do you think I have the problem with? As I assume I should try a ph of 6.0 to make certain things more available?

Thanks for the feedback guys

Apart from my problems early in growth, all my coco grows have outperformed my soil grows...especially in yield and vigor. (cant really compare smell/taste, thats personal opinion) So if its hillbilly, that's how I roll Although maybe I should consider starting my seeds in soil plugs, then transplanting to coco....Food for thought anyways!

dont use nutes for around first 2 weeks, that could be the problem rhizo is ok but seedlings dont need the nutes for a while

I have 4 seeds in coco now, 10 days old (since cracking) nice and healthy only started giving them rhizo 2 days ago.

Feeding too early is most likely my continuing problem, as it must have something to do with my schedule, which stays the same (as does the problem)

TicKle, would you be kind enough to post a pic of your 10 day old seedlings? I just want to get an idea on what stage of growth you start feeding, as everyone seedlings seem to grow at very different rates! Then maybe I can go about curing my"coco retardation"

Take it easy

I grow in COCO using HESI nutes..........feed TNT at 2ml per Litre from the start, up to full strength within 2.5 weeks. I had the same issues as you are showing in my first couple of attempts, drove me crazy! After speaking to a few people on here I started the doing the following:

tap water is left sitting out for at least 24 hours before use
I add 1 tea spoon of epsom salts per gallon every feed......stop with the epsom a few weeks from harvest
flush with plain ph'd water every 5 feeds

thats it, works for me anyways, last three plants ha ve all been nice and healthy from start to finish.

UKHomeGrow said:

I grow in COCO using HESI nutes..........feed TNT at 2ml per Litre from the start, up to full strength within 2.5 weeks. I had the same issues as you are showing in my first couple of attempts, drove me crazy! After speaking to a few people on here I started the doing the following:

tap water is left sitting out for at least 24 hours before use
I add 1 tea spoon of epsom salts per gallon every feed......stop with the epsom a few weeks from harvest
flush with plain ph'd water every 5 feeds

thats it, works for me anyways, last three plants ha ve all been nice and healthy from start to finish.

Click to expand...

full strength from week 2.5?

i got 16.5 ounce from a plant that never exceeded half strength of the 'recommended' doses, >

View attachment 2304265

https://www.rollitup.org/grow-journals/543220-og-kush-airpot-test-grow.html

be careful and dont fall into the 'more is better' way.

I reckon your feeding too early causing lock up so you are behind from the off, will post you some pics later this evening when the missus brings her i-phone back of the seedlings i got now.

Yes mate, as do most people who use HESI nutes I believe. The TNT complex is quite mild and my plants show zero sign of nute burn. The last three have been perfect, 12/12 from seed, pulled 2.5 dry of each. 12 weeks roughly start to finish. Im happy with that.

By the pics its looks like a magnesium uptake issue. Try a pH of 6.2 to 6.5 and I bet your problems will go away. And the epsom salts ideal as mentioned couldnt hurt either.View attachment 2304303

Now were getting somewhere! Maybe since I have heard that H&G nutes run a tad "hotter" than other nutrient brands I should juts stop being stingy and get some mild feed for the first two weeks. The conversation above is emulated all over the internet, the early feeding coco group and the group that waits for slight deficiency signs, so it makes it bloody hard to figure out a feed schedule. Looks like very different things work for different people....

I also thought it looks like magnesium, (Still has green veins) but then again...also looks like Manganese and Iron to me too haha!

Ill feed tonight at 6.2 at an EC of either 0.6 or 1.0 depending on how they reacted to their last EC 1.0 feeding, and then ill add the smallest dose of epsom salts possible (maybe 1/4 teaspoon to a gallon?)

Should I apply it as a foliar spray or directly into the feed? Just worried about applying it directly to coco, have read abit about it causes problems....Although I have H&G drip clean so that could help some?

Thanks for the help guys, Hopefully they start to shape up over the next week

(Just started germinating a GHS pure kush, barneys farm power kush and another AH#3 just incase though!)

TicKle, that is one damn lovely cola! Very keen to see your seedlings, looks like you have your set-up running like a well oiled machine

Alexander Supertramp, I have a few graphs like that, but the one you posted makes it look fairly obvious to me the optimum ph is 6-6.2, which sucks because all along I have tried so hard to keep in the 5.5-5.8 range. Think I might run on an average of PH6.0 this run and see how it treats me!

ok, got some picture's, these pictures are from tonight, strain is Strawberry Cough from Dutch passion, dropped them in a glass of water for 12 hours, then into jiffy, they sprouted day after, added rhizotonic yesterday @ 1.5ml per litre(day-9) and no nutes yet, will be hitting the nutes very mild as soon as the 2 feeder leaf's at bottom fade,
so they hit 2 weeks old in 4 days, so any day now i reckon they will want some nutes EC-06-08 (my tapwater =04-06, so only a mild hit first time, but will go up from there, am in canna coco. I dont bother with PH as the coco buffers to 6.5 anyway
this is them day3 after sprouting,.


This is them tonight, i had to bury around 3 inch of stem as they stretched quite a bit over last week.

Always wanted to try strawberry cough...think you inspired me to run it next time, they look so healthy! 90% of that would have to do with their caretakers green thumb of course

Thanks so much for posting them up mate, a picture speaks a thousand words! From looking at them im relieved to so that my seedlings arent always stunting as bad as I think, although Im sure unhealthy seedling equals slow beginning of Veg....I can also see from the photos that (unless its just the pictures tricking my eyes) you let your coco dry out much more than I do, to the point were the top layer has gone grainy.

Now I know you want to let it lose abit more moisture than normal in the early stages to promote root growth, but I had no idea that I should let it get that dry! I think you just proved to me that I'm suffocating the poor little girls, so ill stick to my new feed plan, but will leave the feeding for another night or two

Im so glad I started participating in this forum now rather than just reading page after page, I've read so much conflicting information over the years all over the web, books etc, but this is really helping consolidate what I need to do!

Just Went out to check on the girls-

Heres the healthier of the two seedlings (I'm assuming she will be showing improvements before the other)



What do you think? looks to me like its improved a tad, greening up a tad in the middle and the stems beginning to get some girth. Not sure if its due to raising the light, or raising the feed EC haha

Elder1 said:

Now were getting somewhere! Maybe since I have heard that H&G nutes run a tad "hotter" than other nutrient brands I should juts stop being stingy and get some mild feed for the first two weeks. The conversation above is emulated all over the internet, the early feeding coco group and the group that waits for slight deficiency signs, so it makes it bloody hard to figure out a feed schedule. Looks like very different things work for different people....

I also thought it looks like magnesium, (Still has green veins) but then again...also looks like Manganese and Iron to me too haha!

Ill feed tonight at 6.2 at an EC of either 0.6 or 1.0 depending on how they reacted to their last EC 1.0 feeding, and then ill add the smallest dose of epsom salts possible (maybe 1/4 teaspoon to a gallon?)

Should I apply it as a foliar spray or directly into the feed? Just worried about applying it directly to coco, have read abit about it causes problems....Although I have H&G drip clean so that could help some?

Thanks for the help guys, Hopefully they start to shape up over the next week

(Just started germinating a GHS pure kush, barneys farm power kush and another AH#3 just incase though!)

Click to expand...

I add the epsom salts to a cup of hot water from the kettle to make sure they dissolve fully, then add to the feed.......PH after everything has been added.