librarygirl
Look It Up
I got my new tank recently (one month ago). Everything has been fine untill I changed all 3 filter cartridges at once (my mistake). after 2 days some fish died, most of the rest fish look lethargic. what shall I do?
Hi! Unfortunately you tossed your beneficial bacteria so it'll take some time to re-establish. I'd treat this as a fish-in cycle at this point (there are links above in the guide to fish-in cycling). DO you have a test kit? A good liquid test kit is a must to see what's happening in the water. Since some fish are showing symptoms of possible toxin exposure (ammonia and/or nitrite) I'd start with a 50-60% water change with dechlorinated, temperature matched water. Then with your test kit you'll want to test the water daily for ammonia and nitrite and nitrate. Any time ammonia or nitrite hit .25, do water change(s) to get them as close to 0 as you can. Keep doing this until ammonia and nitrite can stay at 0 on their own, then you can just go back to your weekly water change. I don't know how long this cycle can last, so just be diligent in checking the water and doing water changes as needed. Hope this helps. If you have any more questions just ask.
*Edit: Oh, and what size tank and what fish are in there? If it's heavily stocked the toxins will rise more quickly.