| | Re: HELP!!!!! Nitrite spike in established tank after treating with MELAFIX
Actually it does not harm the bio-filter, have never personally had an issue, or heard of anyone having an issue with it. Was anything changed? Substrate, filter media, big bio load change, large plant mass change? I would look at that type of thing. If it was an established tank then there had to be a large upset for the bio-filter to get screwed up! Throw some prime in there and wait it out!