Trying to grow 4 CBD plants in one DWC

Hey guys

Maybe I'm being a little ambitious but for my latest project I'm trying to grow 4 plants in one 70L DWC. 2 of them are Humboldt Blue Dream CBD (the ones on the right) and the other two are Dr. Seedsman 30:1 CBD (the sick looking ones on the left).

In the following pics you can see the Blue Dream CBD is doing alright but the Seedsman is not doing well


Other info about grow:
Using 4 qb288 panels approx 2.5 feet above plants - Was only using 2 panels until a day or two ago
I plan to swap to flower in about a week
Using Current Culture nutes (-UC Roots) + Mammoth and Greatwhite + House and Garden Roots Excelurator and Algen extrat
Roots of both plants look good and healthy
EC was at 0.7 but raised to 0.9
Ph hovers around 6.0
Res Temp is about 19.5 Celsius
Humidity is about 65%
Temp is approx 28 Celsius

I have a couple of theories as to why the Seedsman isnt doing too great:

0. Obviously something is genetically different with the Seedsman CBD plant compared to the Blue Dream CBD - perhaps one has a lot more genetics from hemp and the other from cannabis?

1. I haven't changed the water in about 2.5 - 3 weeks. This is because I initially filled with approx 65L for 4 tiny plants and have set up a pretty basic nutrient doser to maintain an EC level and a PH doser to maintain ph. And I've been lazy. And I kind of want to know how often I really have to change my res especially in Veg. I will change it tomorrow if I see no signs of improvement (recently increased res EC previously)

2. Perhaps I topped the plants a little early they were all looking very healthy untill I topped them. I also probably shouldn't have defoliated as much as I have.

Any help would be much appreciated, thanks guys and happy growing !

bonus secret questions - Im gonna try UVA this run - anyone tried UVA on CBD varieties?

Is that 4 plants in 2 net pots? Plants should not be sharing net pots.

What size is your grow area? Do you use a water chiller?

Algen extract is organic and should not be used.

Stick to the basics. Keep it simple. You are adding 4 different stimulators.

2 plants per pot and wanted to experiment with putting 2 plants in each pot, so far it doesn't seem to be negatively affecting anything.

grow area is approx 1m x 1.5m and yeh I use a chiller, water is kept between 19 and 20 Celsius


Any ideas on the exact cause of the stunted grown in the CBD plants? You think its the stimulators? I thought perhaps the Seedsman CBD plants needed more nutes.

If I was going to try four in one I would only attempt it with clones of the same plant
Pheno's and different plants all have different temperaments

plebschmo said:

2 plants per pot and wanted to experiment with putting 2 plants in each pot, so far it doesn't seem to be negatively affecting anything.

grow area is approx 1m x 1.5m and yeh I use a chiller, water is kept between 19 and 20 Celsius


Any ideas on the exact cause of the stunted grown in the CBD plants? You think its the stimulators? I thought perhaps the Seedsman CBD plants needed more nutes.

Click to expand...

Seems like you got your shit together so not sure myself. Id go back to basics tho and start there.

Different plants react differently all the time. I'm personally done with trying to grow 2 or more strains on the same res.

Herb & Suds said:

If I was going to try four in one I would only attempt it with clones of the same plant
Pheno's and different plants all have different temperaments

Click to expand...

Yeh you're probably right. 4/4 seeds popped so I wanted to see if I could finish veg a little earlier by starting with more seedlings.

Failmore said:

Seems like you got your shit together so not sure myself. Id go back to basics tho and start there.

Different plants react differently all the time. I'm personally done with trying to grow 2 or more strains on the same res.

Click to expand...

Thanks for the help. I'll go back to just A+B and CalMag for next water change and go from there.

Upped the EC to 1.0 and it seems to be making an improvement. I think the issue was caused by a combination of low EC and stress from topping.

Does anyone know if high CBD low THC varieties generally need more nutes?