Ok, I have a wet dry sump/filter now..... I want to buy a new pump for it..... Im looking at 500, 700, 1000 gph pumps..... my wet dry is about 20gal maybe a lil more, and my tank is about 100 gallons.... what pump should I get?? I want to go big, but if I got the 1000gph pump would it work too fast and cause problems overflowing the overflows? Any suggestions comments would be appreciated.