Is filter the problem?

[babyblue4020]

I was wondering if anyone can help us. We bought a used canister filter, we cleaned it pretty good and bought all new filter media. I heard canister filters are bad for salt water. It was used for freshwater before. Our anemone recently died and then today all but one of our fish died because we removed him before this could happen. We think we have lack of oxygen, or something toxic got in the water. I tested all levels and they appear to be normal. Anyone have any advice???

 

[roka64]

I run a canister on my 55 and 125 SW tanks. I like them for the added water volume, and a place to house extra rock rubble and to run media. If you replaced everything, there is a possibility that you may have removed some of the biofiltration when you took out the rings/bioballs.
Judging from your other post, you could have stirred up nasties from the sand bed, overloaded your bioload or when the nem died, it nuked the rest of your tank. It's really harf to tell exactly what happened at this point since there was so much going on at one time.
Don't sweat it too bad, we have all made plenty of mistakes, but you are on the right site and we'll help you get through this.

 

[Kurt_Nelson]

If during that die off, you tested for ammonia and nitrites and saw 0.0ppm, I'd tend to think your test kit is bad. Having that much stuff die off in a tank and have "normal" water levels just doesn't happen. For a test kit, are you using liquid tests, or the test strips that just give you general "good/bad/ugly" type of readings?

I don't think your cannister filter had a thing to do with it. They're not bad for saltwater, they're just not used as often. As long as you keep any sponges in them clean (rinse them at least once a week in salt water), a cannister works just fine in saltwater.

 

[babyblue4020]

I just bought the test kit two days ago. Ammonia was good but nitrates were kind of high.