Holy crap, that's a lot of chili! How many plants do you have?

Personally, I'd skip the slow release stuff and just get a regular water soluble 10-10-10 (+micro nutes) fert and mix it 4 to 1... 1/4 strength.

Use it every other watering until things green up and then use it when they look like the need it again.

If its not overwatering, then some fertilizer would help with the yellowing. I would stay away from foliar spray and Epsom. Epsom salt is useful at times but not a go to, general purpose fertilizer unless absolutely necessary to correct magnesium deficiency.

Are some of your peppers spray painted purple for identification purposes?

All nice looking peppers.

Mark

Doh,

Mark, good catch. I neglected to think about possible over watering of a few of them.

Bill

Its definitely not overwatering (i think), im very sensitive to the watering schedule and always allow them to just start to wilt, and i can see the medium turning a dry color at the top. I have a very low nutrient medium that ive custom made from scratch(mostly aeration). its kind of a cross between a 5-1-1 and a basic potting soil. Lotsa perlite, a little dolomitic lime, lots of orchid bark. The problem may be from a specific set of plants I repotted in a frenzy and I basically just used straight potting soil. I also planted some seeds in that particular batch of soil and it completely frapped out, perfect germination but stunted growth from the outset and turned all yellow. I believe it was "greenall" brand potting soil. total crap! I replanted all the seedlings into new MG seed start mix to hopefully salvage a few of them but im not holding my breath. About 20 varietals all barely putting out true leaves after 2 months. well see if those get any better. I have a HUGE amount of leftover GH flora series nutes that I have been using. they have been sitting for a few years. 15 gallons total, 5 gals each nute. Its possible that I overfertilized last week since I have so much its hard to get a "teaspoon" amount out of the 5 gallon containers. but Im pretty sure I got it right.

@ottawapepper why do you use your nutes at 1/4 strength? ive read this elsewhere but im unsure why I would go that route if my plants are 2-3 months old? I figured this would require a fairly rapid uptake. Im currently growing around 300 pepper plants and about 40 varieties. all hot and superhots. Im running out of room in my greenhouse, Everyone asks my why I dont grow other plants, all i can say is I really like hot peppers!
@habjolokia Hi Mark, thanks for the input. I have some supplemental light (led's that are very weak but designed for plant growth) that are more of an experiment than anything else. that is why some of my plants look purple. its the blue/red LED's. Eventually im planning on adding an array of LEDs to the entire greenhouse and then really trying to push my growing season out. So im curious what type of ferts you use Mark? any name brand? why not use the epsom salts? have you had any bad experiences? Im one of those guys who tends to overdo things so the less is more philosophy is usually very applicable for me.

Littlepepperboy, I use Alaska Fish Fert 5-1-1, alternate with some MG liqua feed but use more of the fish fert. When I repot from starter pots to the next size up or the red solo cups I throw in ground bonemeal and by mid season when they need it its broken down and plant useable.

I don't recommend Epsom unless its to correct an issue. Reason, using ferts with Epsom on top of the ferts will increase salts in the soil which may cause uptake problems that look like nutrient deficiencies when it's not, then to try and correct by adding more ferts causes further problems.

Mark