My tanks have a turn over of around 8 - 10 times per hour, with a high flow rate accross the surface of the water. I use venturi's to ensure maximum oxygenation.I still don't know much about the filtration they need, I can make a strong current with my filter no problem, and I have an air bubble thing
As fo the neons, they can cope with the temp just fine, but they tend to hide from the current a bit. The tetras prefer a slightly slower water, and you will probably find they just sit ina corner.
The applesnail should be fine ( I think). I remember having one in a community tank. it used to spend hours crawling up the filter, jumping into the flow, shooting accross the tank, then going back for more!!!!!
The only thing I would say about the shrimp, is they may have a tendancy to eat the eggs if they roll out of the cave, (but this is just a guess).
rob
