Hi everyone! I need just a bit of your help. This is my second grow...the first one went very well, without any problems. This was in the winter and now we have a hot summer (around 30 degrees C). So my question is about my seedlings...they are not looking very good.
A little info:
Cabinet is 1x1x1,8m big. It has a 400W cooltubed HPS bulb. One ventilator is for air extraction (500m3/h), two computer fans blow air inside. I also have a fan for air circulation.
The temperature in the box is 30 degrees C and the room has 28 degrees C. I cannot get any lower than that.
Soil is bought from the store (Compo sana for flowering plants). I added perlite and two tablespoons of dolomite lime.
The seedlings are in 1L pots.
pH of the soil checks out at 6,7. This was messured from the root zone. I took some of the soil from the root zone and mixed it with destilled water, than messured with a pH meter.
Also the roots look white and there is no sign of root rot.
I water the plants, till runoff appears. Than I wait till the soil dries out (in the bottom). This takes about 4 days. The top of the soil dries out in 1 day.
I water with tap water, filtered through BRITA filter. I also let water sit for 24 hours. The water pH is 6,5-7,0. I didn't give them any nutes.
RH is 50%.
The leaves are yellow and crispy. And it seems like they are drying from the tip.
I am positive, this is not a Nitrogen deficency...because the yellowing started on the first set of real leaves. Cotyledons were green at that time. This was about a week from when the seeds were planted. Yellowing now is also going further on the new leaves.
Now I don't know if the temps are too hot (I know it's not in optimal, but we have a hot summer now), or the soil is too rich for the seedlings and they are burning because of the nutes in the soil. I am leaning towards heat stress.
Any help would be appreciated. And sorry for my English.
Have fun.
A little info:
Cabinet is 1x1x1,8m big. It has a 400W cooltubed HPS bulb. One ventilator is for air extraction (500m3/h), two computer fans blow air inside. I also have a fan for air circulation.
The temperature in the box is 30 degrees C and the room has 28 degrees C. I cannot get any lower than that.
Soil is bought from the store (Compo sana for flowering plants). I added perlite and two tablespoons of dolomite lime.
The seedlings are in 1L pots.
pH of the soil checks out at 6,7. This was messured from the root zone. I took some of the soil from the root zone and mixed it with destilled water, than messured with a pH meter.
Also the roots look white and there is no sign of root rot.
I water the plants, till runoff appears. Than I wait till the soil dries out (in the bottom). This takes about 4 days. The top of the soil dries out in 1 day.
I water with tap water, filtered through BRITA filter. I also let water sit for 24 hours. The water pH is 6,5-7,0. I didn't give them any nutes.
RH is 50%.
The leaves are yellow and crispy. And it seems like they are drying from the tip.
I am positive, this is not a Nitrogen deficency...because the yellowing started on the first set of real leaves. Cotyledons were green at that time. This was about a week from when the seeds were planted. Yellowing now is also going further on the new leaves.
Now I don't know if the temps are too hot (I know it's not in optimal, but we have a hot summer now), or the soil is too rich for the seedlings and they are burning because of the nutes in the soil. I am leaning towards heat stress.
Any help would be appreciated. And sorry for my English.
Have fun.
