Seriously doubt it's magnesium shortage. Leaves are too green for that.

Could be excess fertilizer salts. Or too little water.

Please tell us more about how you are growing them.

Planted dec 9 in starter pellets. Moved 12/26 to small clear cups>1/15 to solo cups with quick draining soil>2/10 to 2-liter containers with mixed soil. Each transplant was prompted by roots curling and then out growing the containers. 16 plants 9-10 of them in the 2-liter containers fit under my 2ft 5000k lumen double strip light, while 5-6 fit under 2 2700k lumen lamps.

Have been using miracle grown diluted with water since around a month old when watering (approx once a week, and started trying to bottom feed about the same time) Had a bout of edema soon after introducing the strip light. Began using a fan on the plants to circulate the air, and it seemed to alleviate the problem. I liked the quick drain soil because it prevented mold problems, but the down side was that everything would be fine in the morning and come evening they would be so wilted that the leaves were hanging straight down... This resulted in many lost leaves after they plumped back up with water

I also found they could seriously droop from cold. My bedroom skyrockets around 85 for hours, and then the heat shuts off at night and can drop pretty low... Up until 2/9 I had housed them directly on top of the radiator for a bit to keep them as warm as possible. Since moving them across the room I built them a tin foil tent to keep them warm

Reading about all the possible deficiencies I sprinkled some Epsom salt around the base and bottom fed with watered down Epsom. It didn't stop the curling, or yellowing and dropping off of lower leaves (the weeks I used Epsom I did not use miracle grow) I bought these spikes today only to realize they are pretty much the same thing as the miracle grow I was using... I was trying to find low nitrate, and something with a lot of calcium, Mag, and boron... I don't know...

My suggestion is to stop with allllll the ferts for a while. Something is bothering them and it doesn't look like lack of nutrients to me.

Everything I've read is saying the severe puckering, the curling, we're all a result of deficiencies

Wow... I just wrote a huge message with that.. The first pic is of mr. Orange, it's hard to tell but all those bottom big 5 leaves are yellow and going to drop. The second pic is of mr black and he's about to drop his big bottoms, and he's the only one that has any blossoms at this point. Mr. Pink is in pic 3, he got 2 spikes and water tonight, as did mr blonde because they were bone dry.

The last pic from above is mr. Noice who is the runt, and got one spike and water. I'm freaking now cause you said to lay off, and I just stuck half of them with these stupid spikes! Check out this close picture on Tetra tho... It's like sugar granules.. Diff than the edema. Rough and on the outside. Been present for awhile-no bugs

And yes. I named my plants. Mostly after the Reservoir Dogs

This doesn't look like a fertilizer issue. I have this exact same problem and it was caused by the spider mites in the picture. Just like in the picture, these spider mites are so tiny that only the largest adults could be spotted without a magnifying glass. I highly recommend you take a magnifying glass to your leaves, particularly the underside and check for bugs.

I believe aphids and others will cause similar symptoms. The bugs prefer the new growth because it is soft and healthy. They chew it up so that when it grows, nutrients aren't distributed properly, causing mal-shaped leaves. This happened to me.

The puckering doesn't look bad to me--it's the first two pictures that looks really unhealthy.

Funny, after growing about 30 varieties and sometimes overwatering, I've only had edema on my jalapeno plant.

!!! So after this thread the next day all the plants I put the fertilizer spikes in started getting purple/silver burns all over the leaves... I did an immediate emergency extraction with a pair of tweezers to get the partially dissolved spikes out... The plants have lost some of the affected leaves but recovered.. MIKE how do you get spider mites????? Where do they come from?? And how do u get rid of them??

And after a few weeks of just water no fert, the curling inward has greatly decreased. Still some yellowing, some random brown leaf wilt stuff, and the curling under is still happening, but the plants growing peppers have nice dark green leaves suddenly.. I do think part of it was over fertilizing I literally water these things like once a week and only bottom feed them

I'm not sure if your plants have ever been put outside, but I understand that spider mites usually travel by wind and blowing in the breeze. It's almost impossible to avoid completely unless you're indoors or in a greenhouse. But they seem to propagate pretty slow.

For the first two pictures posted, I'd recommend getting a magnifying glass and confirming the insect. Different insects will cause the same symptom, but the resolution to them is different. For instance, killing aphids is really easy, but killing spider mites is really tough. While a systemic will kill many insects, food grade systemics won't kill spider mites--the solution is to spray each of the leaves, which is a lot of work--and it only kills on contact, meaning multiple applications is probably needed. Most of the insects I've encountered like to be on the underside of the leaf.

If you do find insects and do need to spray the plants, I strongly recommend against soap based sprays and sulfur based sprays. In my experience they will definitely kill spider mites, aphids, etc. but about 1/3 of my varieties get leaf burn and get damaged. And if multiple applications are required, it basically kills all the leaves on the plant. I recommend neem oil or some other oil based product--the plants seem to handle this much better and not get chemical burns. Hope this helps!

Sorry, forgot to mention, for the first two pictures, it also looks like it could be overwatering. It's a little hard to tell. If the leaves are malshaped, like asymmetrical or not the right shape of a leaf, it's insects. If the leave is normal shaped, but curling upwards, I've seen that caused by too much water.

Took pic of underside of leaf. Shiny crystallized bits. Used magnifying glass and stared for a bit - no movement, no bugs. Had a plant that had mold feeders long ago - microscopic white things that teemed in the soil after staring for a minute so I know what ur talking about ... These Plants were planted indoors with store bought soil dec. 9 and I live in Massachusetts - trust me these plants have never been outside, by an open window, or exposed to pests.

AND they are in quick draining soil (primarily used for cactus), and get fed about once a week!! Bottom fed, so the leaves are never wet and I wait till it's a dry finger deep on top, and dry threw the bottom drainage holes b4 I water