Lights dehydrate my soil

A question from a fellow grower:


I’ve got problems with my grow, my lights dehydrate my soil in no time at all, 60x60x120 tent, 250w MH.

Can you advise me?


There’s lots of different options in this case.
*raise light level
*change light density
*add potting plate
*change soil mix
*add polyacrylamide to current soil mix
*change fan position in grow room
*hydrate grow room
*lower heat in grow room
*change growing style


It’s literally this simple, ready?
Take a piece of cardboard, cut it out to match the shape of your pot. Cut a slit into the center of your circle, and then cut a little hole in the center of your circle.
This will cover your dirt from the sunlight. Just remove the cardboard when watering, and replace when done.
I use to use extra Mylar I had lying around. I don’t really recommend the cardboard, just because it’s porous and I feel like could cause problems eventually. But get creative, find something you can use to cover your dirt and you’ll be fine.



I noticed that the more leaf cover I take out the more this happens. I noticed my black pots were heating the room up, and the roots also. So I taped white paper to the sides of my plastic containers. I went from 82 to 79 degrees overnight. Then when the plants thoroughly shaded the dirt the temp went to 77. Hope this helps a bit. :slight_smile:

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Has anyone every done any test to determine the best amount of
water a pot should hold ?

Curious as I am using a 3 gal felt pot with Pro-Mix HP & 15% Perlite,
Plant is 10 weeks Veg @ 8 inches tall and 3 foot by 2 foot canopy.
Pot holds 1 gal water/nutes, (20 cups in with 4 cups run-off – 20% Run-Off)
Water every 3 to 4 days.

Anyway just curious if there is a optimal water retention amount

I use promix, my seven gallon pots take two gallons with minimal runoff.


Possibly, but I am unaware. A good place to look would be the manufacturer your media. They might have saturation statistics.

Thanks, I’ll check there. Was really just curious if any MJ specific studies had
been done to find an optimum, probably not as there are far to many variables.