All of our water works on a slightly more souped up version of this. We do have to remove frogs and debris from the filters we've got on, and I boil the water my children are drinking, but it seems to work OK. We do run dry at times, I keep a supply of Sainsbury's Value bottles in the house all the time and we have a license from SEPA to pump water out of the river if we need to, but in general it's pretty good. The fish sound like a plan!
I would have thought it would be quite straightforward to put a pipe on the tap of one of those big containers and pipe it into an old lick tub with a ballcock on so you weren't worrying about filling the tubs really often in hot weather.
I've never thought about it until Bramblecot mentioned it, but our sheep definitely prefer to drink with their front feet up on something too, no idea why!