Trying to grow in a 4X4 sunhut. Using a 400w light w/vented hood. 8" fans for intake and exhaust. Using grow medium last ph was around 5.7. I seem to be having constant mg problems. Plants start out great then start to yellow in about 2 weeks. Foliliar feeding with epsom salt seems to help....but I never seem to get a full recovery. I guess my question is how often can spay with epsom salts. Every thing I have ever read never mentions how often. Until I bought the sunhut I grew in a closet. I had pretty good success. Since I have been using this sunhut I can't get anything to grow more than a few inches. I have really tried everything (believe me) to try to fix this...short of moving back to my closet. Any help is greatly appreciated.