Another pic. I also haven't noticed any pests other than some ants.

I would say that damage originated from some environmental case and later the leave tried to brush it off.
I would not worry about it.

When you say "a dose" of epsom salts per week, how much are we talking about?

Some of my chili pepper's leaves look like that as well, no added epsom salts though.

Id guess around 1/2 tablespoon sprinkled around each plant.

Can I ask why you think it needs all that much Epsom Salts? It is possible to overdose plants with mag sulfate and the zippering on the fruit in your pic is one of the symptoms of that as well as of excess nitrogen.

The zippering on the fruit as well as the leaf deformatives can also be caused by excessive humidity at the time of pollination/ development. In other words, environmental damage.

But I would recommend cutting way back on the epsom salts. It works better when pre-diluted in water anyway but it isn't normally needed more than once or twice a season.

Dave

I'm just going by what the lady at the garden center said. She said she did it weekly with good results. They've had nothing else given to them except what was already in the miracle gro

Cut down on Epsom salt and see if the plants condition improves.

You might check this thread in the Hot Pepper forum. A couple of us are battling Chilli thrips that cause this sort of leaf damage, and more. Your plant looks to be in the beginning stages.

http://forums.gardenweb.com/forums/load/pepper/msg0511302622994.html?23

Clipping off all the damaged leaves and treating the plants with insecticidal soap seems to be working for me.

Excess magnesium can induce a calcium deficiency and those plants exhibit symptoms that could be those of a mild calcium deficiency. A half tablespoon per week is way too much.