i dont have any external filters but i have an eclipse 29 gal system w/ a built in filter and i just found out (at a "fish only" pet store) that i needed r/o water. also i found out that i needed a
protien skimmer and some live rock. i added those and now my tank is looking great now. accually my fish are looking better and my
yellow tangs HLLE is looking better. the clownfish might have died from bad water and my mexican wrasse ate them(it has eaten other fish before). i am probably going to try to get just one clownfish instead of two. but right now i have different fish typed then i did, i have a yellow tang, a mexican wrasse, a three striped and a yellow tail damsel, a spotted hawkfish, and 2 hermit crabs.