The most common source of issues stems from the fact peppers don't tolerate wet feet well. For that reason, watering correctly and getting watering intervals right is more important than when growing plants not so sensitive to wet feet.
Try this. Establish your plantings suck that the bottom of the pot is nestled several inches into native soil (the earth). From the perspective of hydrology, this simple trick turns your 'container' into a mini 'raised bed'. Reason: The technique employs the earth as a giant wick, which will 'pull' all excess water that would normally perch in the container, out of the container into the earth.
Use a wooden 'tell' made from a 1/4" wood dowel rod (any hardware for $2) to test moisture levels deep in the pot. Cut the 48" rod in 2 or 3 pieces and sharpen all ends in/with a pencil sharpener. Push it all the way to the bottom of the pot. When it comes out almost but not completely dry, it's time to water.
Don't forget that fertilizer is an essential part of your endeavor.
Another question that should be asked is, does your home have an ionic exchange water softener (uses salt as the exchange medium). If yes, you need to find another water source or route the plumbing from which you get your irrigation water to bypass the softener.
If it gets too hot, figure a way to shade your containers. Actual soil/root temperatures should be 85* or less. FWIW, moist soil usually lags ambient air temps by 10-15*.
Al
