Curling Leavings, Brown edges and yellow tips

[sassyrope]

Hi All,

 

Setup is a 0.6m x 0.6m x 1.6m tent in a cupboard. Its running a 6 inch inline fan and carbon scrubber, 400W (now 250W) MH. I think the major issue is temperature with the seedlings getting around 32 degrees. Think the main issue is the intake temps and not sure how to get it lower as there is definitely good flow. 

 

The leaves appear to be curling down like they are being overwatered. I make sure the soil is dry before re watering (using small eye dropper twice a day). I changed it to once a day but found all the seedlings dried up in the morning so hence dont think its over watering. 

 

Does anyone know what's causing the curling?

 

Also one of the plants now has a brown edge on the leaves but i think thats due to being under watered.

 

Also whats the cause of yellow tips, I dont believe its nute burn as the soil has no nutes and is safe for seedlings.

 

Any help would be appreciated.

 

Sorry for the bad photo the light is screwing with the camera.

[drunkuncleharold]

what soil are you using????? and your fresh air exchange should be 5x the volume of the grow area in 1 minute. This not only extracts heat, but also helps draw in CO2 for you plants. Make sure you have fresh air inlet at the lower part of your grow area

[sassyrope]

The soil is osmocote seedling and cutting mix. https://www.scottsaustralia.com.au/osmocote/osmocote-professional-potting-mix/osmocote-professional-seed-raising-cutting-mix/

 

The fan is a 6" centrifugal fan. According to specs it should replace it 24x every minute. It has a fresh air at the bottom with an additional fan to try and help and blow the air over the plants.

 

what soil are you using????? and your fresh air exchange should be 5x the volume of the grow area in 1 minute. This not only extracts heat, but also helps draw in CO2 for you plants. Make sure you have fresh air inlet at the lower part of your grow area