I personally believe that many people have far too much current in their tanks - a belief I've developed through keeping gouramis, tetras and bettas, all of whom prefer low current in their tanks.
I think it can tire fish out, particularly if its so strong, they simply can't get away from it, but it depends on your fish. White Clouds and danios would probably cope fine; gouramis and angelfish would hate it.
Also, someone was telling me the other day that too much surface aggitation can encourage the growth of certain types of algae ( ? )
So, keep the outlet nozzle of your pump just at the water surface so you get a bit of disruption to the surface and aeration. But keep the pressure sufficiently low that the fish can easily swim against it. Also make sure that there are areas in the tank with less current, in case your fish need to rest.
As for heat, it could be a problem but many species are more tolerant of the heat than others. Tetras, gouramis and bettas, SAEs etc. seem fine with very high temperatures. Corys and other bottom feeders may have a problem and I know my livebearers have a problem with it. But your fish, if acquired locally, might be better acclimatised. Ask around people in your immediate area and find out what they do.
The problem in Britain was that it was the hottest summer since records began. We simply aren't used to the heat and don't know how to manage it. Our houses are built to keep in, not let it out! Also, our fish are used to Britains cooler temperatures. It's a totally different scenario to living in a hotter country all the time.
