Two Plant Problem

Hello folks, I am currently growing two autos in pure coco in a 7 gallon fabric pot. Grow Tent is a Secret Jardin Dark Street 90 (90cm X90cm X 170cm). I'm running 5 CLYU 048 cobs powered by an ELG 240 driver. Running them at 48watts each. The carbon filter is a 4 inch Rhino Pro with an RVK fan.

The plants are FasBerry and BlackBerry.

This is basically my second grow and the first one was an almost disaster as well. I am using the Advanced Nutrients Sensi Coco line currently.

I'll start from the very beginning. I started feeding them with 1ml of the nutrients from the end of week one.
The leaves started curling for the BlackBerry and I was asked to flush the coco as my input ppm was 69 while runoff was around 280+PPM. I stopped giving them nutes for a week after the flush but now the leaves are turning slightly yellow.

During the second week of vegging I had some problems with the environment, I started with 20-4 light schedule, then went 24-0 for couple of days then 18-6 as the tent is in the bedroom and our baby sleeps with us in the same room. During the lights off, the temps would be around 14-15C while humidity was around 70-80%. I got a carbon filter and a fan speed controller and now the temperature are a bit more stable.

They are right now in day 4 of the third week of vegging, the temps in the grow tent are around 19-21C while humidity is around 55-65%. I fed them with 0.5ml of the A and B each day before yesterday. I didn't feed them yesterday because I thought it could be because of the overwatering? I used to water them with 2 litres of tap water which sits at around 69 PPM. I do not have a pH meter yet but when I did I remembered the pH was around 6.2 after adding the nutes.

I've ordered AN calmag as well which should arrive by tomorrow hopefully. I'll also start LST soon when the gardening wires arrive.

Thanks for any help guys.

It will be hard for someone to help if you don't have accurate info about the PH.
You need to get another PH pen if you are going to grow in coco.

Yeah im planning to get the bluelab ph meter soon.

faultfiction said:

Yeah im planning to get the bluelab ph meter soon.

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Great idea.
Some leaves have yellowing between the veins and it might appear to be a deficiency. Something like magnesium would give that type of look but if the PH is off it could be that nutrients are being locked out.
Whatever PH pen you get remember to keep it in the proper solution to protect the probe when not being used. A common mistake people make is not caring for it properly.
Good Luck!

Looks like magnesium deficiency caused by PH lockout (a PH lower than 6 or greater than 7 locks out Magnesium)

Thanks for all the help guys. I have given them 2ml of calmag in two litres of water yesterday. Hoping things turn better in a few days.

faultfiction said:

Yeah im planning to get the bluelab ph meter soon.

Click to expand...

just order the general hydroponic ph kit on amazon for 15$ and it will be delivered in 2 days with prime.

NwGKenny said:

just order the general hydroponic ph kit on amazon for 15$ and it will be delivered in 2 days with prime.

Click to expand...

ill check if they have it available in the UK. Thanks

I figured the problem and updating just in case anyone wanted to know. It was gnats that caused the problem.

What I did wrong was a stupid thing to begin with but it did help me learn a lot about damage control as well.

I planted my autos in 7 gallon pots straight from the seedling cup. Overwatered them. My temps were 18-19C while humidity was always around 65%-75%.
Once I found out about the gnats I stopped watering and applied neem oil. The temperature went back up to 25C with humidity now down to 45%. I removed the Gnat infested plant, have some BTI on the way as well for the other Auto which seems to have bounced back now. Going forward I'm not going to be growing in anything other than 2 gallon pots.