Do you have chlorine or Chloramines. The flashing is a sign of gill irritation, this is often due to parasites as mentioned, but can also be due to ammonia burn. Immediatly after a water change test for ammonia. If it shows up then you probably have chloramines. You will neeed to switch to Prime or amquel plus as a water conditioner.
Stress coat may also be the problem, but I never had any trouble with it. the aloe may be caoting the gills and causing irritation. I'd quit using it for now and see if that helps as well. Like said I never had trouble, but I also never used anything more than the bare minimum needed to neutralize chlorine. Don't be decieved by the label. Almost all water treatments claim to be effective for chloramines but only a couple really are. And your fish do not need moisturizers (aloe) added to their water. Dry skin is seldom a problem in a fish tank.
There does not have to be visible spots on your fish for parasites to be present in the tank. so once ammonia burn is eliminated as a possibility, and you know it's not your water conditioner causing the flashing. I'd go with the next most likely culprit which is Ich. Once you run a full coarse ich treatment (no shortcuts, no mishaps) then if the problem still exists I'd look for the more obscure possibilities like gill flukes. With the sole symptom being Flashing at this point there are a lot of possibilities.
HTH
Dave