First time - having issues in coco

Hello - first timer looking for some guidance - thanks in advance for any insight.

Strain: Blue Dream (Garden of Green) - started from seed
Method: Coco w/ perlite (70/30) and Dr Earth 4-4-4
Vessels: Plastic starter pots
PH of Water: typically water with 6.5
PPM/TDS or EC of nutrient solution NA
Indoor - 2’x4’ tent
Light system: Spider Farmer SF2000 set at 40% at 22" on 18/6
Temps; Day 74 Night 72
Humidity; Day 40 Night 42
Ventilation system; two 4" in-line fans, one exterior feeding, one interior extracting
Humidifier on low 24/7
Co2; No

I’ve got a pretty obvious lightening of leaves in one of my seedlings. This started 3 to 4 days ago. After some basic research I have two guesses that fit my set of variables: either the medium PH is too high, or I may have simply caused some discoloration by aiming my humidifier directly towards my plants.

I have been watering with dechlorinated tap water PHed to 6.5 up until may last watering. About 48 hours ago, I watered each plant with 2oz, PHed to 6.0.

I’ve quickly learned that there is a fine line with water and coco and moisture levels. There is the possibility that I let the medium dry too much. Could that possibly change the PH?

I also should mention that I drowned my first set of seeds so I am gun shy with the agua.

These pics are at 8 and 9 days from sprouting from the seeds.

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The color in your leaves looks good to me. At this point, I’m gonna say that you might want to drop your lights down a little bit. You’re gals are a bit leggy. When you eventually transplant, you are probably going to want to plant them a little further down and build your medium up a bit to support their main stem.

I’m also a little gun shy when it comes to watering. I’m going to let someone else here chime in with their two cents when it comes to your coco and ph.

Coco should be watered to run-off and ph should be around 5.8, I believe.


@Baz4 is right keep the ph in between 5.8-6.0 in coco. I’m also watering/feeding every day from seed to harvest at full strength. I’m in straight coco


This is definitely applicable, and will catch up with you in a hurry if not close to where it should be. If you don’t have something to test, I would make a priority. Cheap one on Amazon will work.

Do you know if your coco was buffered? If not, make sure the coco you transplant to is. And get yourself some calmag, you will need it in coco.


Calimagic will do you wonders, light green new growth can indicate rapid growth, just keep a eye on her, if you’re working with unbuffered coco try to get your transplant coco buffered, but if your too far along a combo of Calimagic 4ml/g and canna coco a+b should work for you, just dilute your ec so you don’t burn your babies. I also like to do a very light foliar spray of calmag to help keep those nutes topped off while their roots are so small and sensitive

And be sure to have some air flow in there to fatten those stems up!

@OlyBoy98503 The lights were at 30% and 28" until recently. I just lowered them and increased the output about 4 days ago when I realized the situation.

@dbrn32 @Blade I am not sure if the coco was buffered. It is a premixed product from Fox Farm that is supposed to be strictly coco and perlite. I can check the packaging later.

Regarding a few other points in this post:

I will work towards learning about ppm/tds and ec with coco. If there are any resources I should focus on, feel free to mention them. Thank you.

I do have decent air flow, I have an oscillating fan on 24/7. I used a weak USB fan for the first week when the sprouts were tiny and delicate, recently switched over to a normal sized oscillator.

Thanks again all.

If you’re unable to find a answer on the buffering feel free to email fox farm, they respond pretty quickly and will have the necessary info. Best place I learned about EC for coco was cocoforcannabis,com goes very in depth

What coco. Is it cocoloco. If so thats the problem. Cocoloco needs to be buffered before use. Needs washed and aall. Almost killed a plant with cocoloco and i even washed it buffered had ph set coming out nice and a week of plant growing just kept looking worse and worse.

@Mark0427 @Blade @dbrn32
According to the Fox Farm website, their 70/30 coco-perlite product is buffered.

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That coco looks dry. Coco should never be dry. And make sure to add cal mag to water that’s as close to ph 5.8 as possible. Water to runoff.

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Update - dropped PH to 5.8 when watering, added CaMg.

Things are looking better in general. The yellow seems to be clearing up a little.

Tips of leaves are turning down a little…too much water?