I had a tank disaster in an established 140G about six weeks ago, and I think it was caused by a Rio. The problem started when the overflow clogged with a big snail, and the sump went virtually dry. A Rio 2500 driving the skimmer continued. I discovered it later, and the tank didn't look too bad. Corals were a little droopy, but basically fine. Unclogged the overflow, refilled the sump, and started up again. That's when the problem started. Over the next several hours, disaster set in. I lost several corals, all other corals were gravely injured, all snails died, BUT the fish were NOT affected whatsoever. I tested the water for copper (Salifert) a couple days later and it was OK. I suspect the Rio, but the seal wasn't broken. Things are much better now, and almost all corals are 90% back to pre-disaster state.
If Rio's suck, what else does anyone recommend? After reliability, reliability, reliability, there's noise (Rio's are LOUD), heat transfer and price. What's best around 700 GPH?