This is my first grow having trouble with my seedlings. Heres the info to start Grow Space: 45" W x 22"D x 60" high painted white armoire Light: 400w MH 18 hours on 6 off. Light is 19" away from the top of the plants. Hand test was fine at 8" Humidity: 35-45% Temperature: 75F-84F most of the time 79 How are the temperature so high even with my overpowered fan? Fan: 400CFM inline; fan is at the top above light exhausting through the back of the armorie, passive intake about 10" by 8" at the bottom of the armoire Strain: Either Black Bubba Kush or NYC Diesel Bag seed possibly both Soil: Fox Farms ocean forest with 25% perlite Germination Method: Paper Towel Growing method: SCROG The leaves have been browning and curling up consistently since they started to sprout. From the research i did online i believe that it was the ocean forest causing nuts burn with over-watering as a catalyst. I have since cut down on the watering to prevent the uptake of nuts by my plants, but they have not responded well. I water about every 3 days with just light sprays of distilled water. The second plant of mine looks slightly better than the first. This can be explained by the fact that it was planted about a week after the first and by then the first one already had problems. What is the cause of my leaves yellowing, browning and curling? Should i scrap these and germinate new ones in light warrior? or wait to see if they survive. How can i reduce the temperature in my grow armoire? Pictures of the armoire are outdated i have since connected the exhaust duct to the top back left of the armoire. Ducting does make sharp turns. I have also cut through the bottom to expand halfway into the bottom half and the containers now sit in the drawer. Pictures of the seedling are two different seedlings. The first one is thinning and growing more vertically with much more damage.And the second one has longer leaves with less damage.
Your fan takes away the hot air from the light, but consider this: there's no hot air in space and yet the sun heats our planet pretty well. The 300w light is so close to the plants that the heat radiation is strong enough to make the temperatures that high. You could pack the back of the cool tube with ice, and the head from the light would still be there 10 inches below it. Your humidity values are presumably not for the humidity inside the cloches but actually inside the general area. The covers over the plants will make it much more humid, and hot, and stale in there for the poor seedlings. You need to raise the light, about a foot. If you can't do this, you'll never be able to grow in this space with it anyway. You need to remove the plastic covers so the desk fan can blow fresh air onto the seedlings. You are possibly right about the nute burn and over watering. Those pots look massive, so it is so easy to over water these plants. they probably use about a tablespoon of water a day or less to stay alive right now, but it's so hard for a tablespoon of water to get lost in all that soil. Really plants this small need to be in a suitable container, like 2 inches or less, until they have rooted, then repot them into these. Give these a chance to get better, and if they give up the ghost in the next 48 hours then germinate some new seeds but keep the light away from them while they are still babies, and avoid making the soil wet just try to keep it moist. If they aren't too hot because the light has been moved, they will tolerate a little dryness and better than a lot of wetness. I have recovered plants from being this bad, but they are going to be stunted for a while at best.
I am absolutely no expert, but I have had similar problems with my seedlings. I discovered that my water had PH at 7.5 Now I water only at max PH 6.5 . Since then, I have not had problems with my little Angels (pic 8 day old seedling) Sent from my iPad using Grasscity Forum