After hearing encouraging talk of coco grows being fast and easy, I decided to started some seeds in coco and hopefully have a successful indoor grow.
I hydrated a compressed brick, rinsed fines & grit. Buffered with calmag & pH to 6.2. As well as added some perlite.
Now the seedlings are slow & looking very sad. pics below - 4 x cups at 4 weeks old.
I could use some help guys 
@brewer76, how offend are you watering them and with what? What height and strength is your light at? That will get things rolling and maybe a coco grower will wander by.
It looks like their in a hot mix but I don't do coco, it'll get sorted.
Thanks @woodi2. I started feeding a A&B Coco Nutrifield product about a week ago. starting with a 1/4 stength dose & increasing to their seedling recommended rate today.
Water & feeding twice - Friday & today so 3 days at this rate. I'm expecting 3 day intervals is OK at this early stage?
I'm on rainwater with 0.02ec. So I've learned to add calmag to my water to get it to a base 0.4ec.
The feed today at suppliers seedling dosage rate brought feed EC up to 1.3. Is that too hot?
Nutrient solution pH is low 5's after makeup. I'm using Sodium Bicarbonate as a pH up solution, I've also heard this isn't ideal as sodium can inhibit nutrient uptake. I plan to grab some KOH when I return to work and make a solution with that for future use.
Its in a 2x5' tent, 200W SF2000 LED is at opposite side of tent at ~ 40% output, diagonal straight line maybe 1m from the light to the seedlings. I'll get a pic this arvo after lights on.
Temp in the tent is cool, 20c @ 75% RH during lights on, down to ~ 13c lights out.
@brewer76 Hey mate, You have a few things fighting each other at this point. First and probably the biggest is that those seedlings are not ready for 1.3ec, at most you want to be giving them 0.4ec total. You also want to be feeding them daily, coco cannot be overwatered as even at fully saturated still retains enough oxygen to keep the roots happy. You want your PH to be at 5.8-6.0 since you are in early stages you want the plant to be in that range for uptaking the correct nutrients, 6.2ph is more towards the ideal flower ph. And lastly you are a bit on the cold side, 20c is baseline for happy, you really want to be in the 25-27c range lights on and no less than 18c during lights off. The cold temps will be stunting their growth at this stage. Your RH is fine and about where you want it but if you fine tune those other factors I mentioned it should get you back on track.
I feel like a, like a slice of butter... melting on top of a big-ol' pile of flapjacks... yeah.
Hey @bubblehok, yeah temps are hard to keep up at the moment.
I'm running the lights from 4pm onward to gain their heat overnight.
The buckets under the racks are all heated water ~ 30c running 24 hours. It gets fucking cold here in alpine Aus.
OK so I've watered again this evening with 0.4ec calmag only at 5.8ph & 24c water. This should reduce the substrate ec right.
What are your thoughts on using calmag in rainwater to get the base mineral content? Or should I just use the A&B to 0.4ec?
I've also taken to warming the water to 20-25c rather than straight from the tank <10c.
pic below for distance to light.
I've been watering daily at 0.3-0.4 ec, 5.8 pH with alternating calmag / nute additions.
Not much growth in the last week and two of the seedlings have died, the others seem to be just hanging on.
The soil veg pot in the same tent seems to be happy & growing OK. (Day 30 veg today) Do we count days of the stage or overall growth? in terms of overall its day 80 from sowing seed.
Still cold in the tent and getting colder overnight temps, its been sub zero a few nights this last week & not even winter yet! I've ordered some immersion heaters to increase the water bucket temps & radiate more heat to the tent.
I've been watering daily at 0.3-0.4 ec, 5.8 pH with alternating calmag / nute additions.
This could be part of your issue. In coco you should be feeding approximately the same feed every day. Cal/mag alone isn’t going to do much feeding on your plant. At this stage in the life cycle you should be feeding at aprox .250 to .400 EC with a balanced nutrient and watering to approx 20% runoff daily to remove any excessive nutrients and waste. This means your cal/mag and the A & B feed should be in the same solution and you should water with that every day in coco. Soil provides nutrients, coco is inert and has no nutrients so it needs daily feedings. Hopefully this will turn that hesitant seedling to an active grower
Random acts of kindness make the world a better place
This could be part of your issue. In coco you should be feeding approximately the same feed every day. Cal/mag alone isn’t going to do much feeding on your plant.
What was I thinking! Thanks @monkeydo. Lets see how they go now.
Is it OK to store made-up nute solution for a few days? if so, are there any storage considerations?
I've been making up ~1 Litre solution at a time, these cups are only taking a small amount of feed daily so the solution is lasting say 3-4 days until I make a fresh lot.
Now I'm wondering if this might be also a problem...
Our forum is free to join. We are an international cannabis forum that helps people all over the world grow their own personal supply of cannabis. Through our site you will find cannabis breeding forums, cannabis deficiency forums, indoor cannabis growing forums, and much more.
We are a home growers cannabis forum, and we only allow people who grow cannabis for personal use to be members. Our mission is to help you grow your own cannabis. We do not buy/sell/trade cannabis, or equipment for growing cannabis. Our site is strictly a cannabis smokers forum, cannabis growers forum and forum for medical cannabis users.
Use our guides on how to grow cannabis, cannabis grow diaries, and growers forum to find all the info you need to learn how to grow your own cannabis.
Any member who is suspected of growing cannabis for commercial gains will be banned immediately.
Please read our forum rules, and enjoy the site.
Find us on all social networks! Just search for Percys Grow Room