Stress coat, novaqua, aqua plus...they all have some form of mucus protective slime stuff in them, or aloe or whatever.
I remember my manager relating an incident to me about a customer who claimed the stress coat killed his fish. He had a marine aquarium that was over-stocked, put in some live shrimp for food, never did a water change, and basically killed the entire tank with an ammonia spike. But my manager called Aquarium Pharmisuicals about the Stress Coat, and apparently AP told her it was impossible to OD and kill the fish with Stress Coat.
I will say, it is plausible that the aloe might somehow irritate a fish's gills and make it difficult to breath. If there is any research or articles supporting that theory, I'd like to read them. If anybody has any web-links related to this subject, please post them.
From personal experience, I have never had any problems with any fish regardless of the amount of novaqua, stress coat, or aqua plus I may have used. Thus far all the fish I've obseved while using the stuff were fine and thrived, or died of totally unrelated causes.
If there is anybody out there totally worried that aloe may damage their fish, sodium thiosulfate is a fish safe dechlorinator. I don't know where you could purchase sodium thiosulfate except from a chemical manufacturer like Fisher Scientific. You'll have to dechlorinate your water before hand, adding the sodium thiosulfate dropwise and using a chlorine test kit to monitor the levels because it is possible to OD on sodium thiosulfate to toxic levels.
~~Colesea