Can anyone help determine what killed fish after water change?
- Thread starter Fish Frenzy
- Start date
Because HOB filters are cleaned more often, it is not usually the case (the flow slows if too dirty which usually facilitates cleaning).
I suppose if you had one and didn't clean it allowing flow to become almost zero.
It most often happens with canisters because they are not usually user friendly to clean, so aren't cleaned out enough, they sometimes go a month or more without cleaning, allowing them to fill with detritus and become nitrate factories, so then if there "is" an outage the gunk quickly becomes an anaerobic mass turning to H2SO4.
I suppose if you had one and didn't clean it allowing flow to become almost zero.
It most often happens with canisters because they are not usually user friendly to clean, so aren't cleaned out enough, they sometimes go a month or more without cleaning, allowing them to fill with detritus and become nitrate factories, so then if there "is" an outage the gunk quickly becomes an anaerobic mass turning to H2SO4.
Thanks. Especially since I'm about to run my first canister. Another good nugget of information I've gained before even plugging it in.
Nothing obvious jumps out to me. The fish death you describe resembles ammonia stress, pH shock, or temperature shock, but I don't read anything in your description that indicates those things, and no way to know without water tests.
Nitrates at 80 is very high imo, but my understanding is they would have to be a good bit higher to explain the sudden deaths in your scenario.
As for canister filters, I've run mostly (though not all) canister filters for years. My maintenance interval for them varies on different tanks but none are cleaned as often as once a month, mine simply don't get dirty that fast-- I've checked. The most frequent one is more like every 8 weeks, the others much less, and my nitrates are low, typically 5 ppm. Whether a canister filter is a 'nitrate factory' or not depends-- size and number of filters per size of tank and size and number of fish, how you set them up, how much and what you feed, etc. That said they do need regular maintenance, which does typically affect nitrates, but there isn't a one-size-fits-all interval, it might be once a month or once every six months, it depends on a lot of variables.
There's a way to size and set up canisters to actually process and reduce nitrates, but I've seen threads where someone buys a biological media promising to reduce nitrates, expects it to work almost immediately-- it doesn't and you shouldn't expect it to-- then they say nitrate reducing media is "snake oil" after a week or few weeks. They don't understand that part of the cycle. Ammonia and nitrite removing bacteria can cycle in weeks, less if you seed your filter with some mature media. Nitrate reducing bacteria are more touchy, take months to "cycle", even though ammonia and nitrite are already cycled, and there are common practices that can short circuit them. Of course, there are other ways to get your tank to process nitrates than trying to get your filter to do it, plants, an algae scrubber, etc. (except DIY, algae scrubbers tend to be expensive from what I've seen)
Whatever the case, I run canisters, do large but longer interval water changes than some do, and I have low nitrates.
Nitrates at 80 is very high imo, but my understanding is they would have to be a good bit higher to explain the sudden deaths in your scenario.
As for canister filters, I've run mostly (though not all) canister filters for years. My maintenance interval for them varies on different tanks but none are cleaned as often as once a month, mine simply don't get dirty that fast-- I've checked. The most frequent one is more like every 8 weeks, the others much less, and my nitrates are low, typically 5 ppm. Whether a canister filter is a 'nitrate factory' or not depends-- size and number of filters per size of tank and size and number of fish, how you set them up, how much and what you feed, etc. That said they do need regular maintenance, which does typically affect nitrates, but there isn't a one-size-fits-all interval, it might be once a month or once every six months, it depends on a lot of variables.
There's a way to size and set up canisters to actually process and reduce nitrates, but I've seen threads where someone buys a biological media promising to reduce nitrates, expects it to work almost immediately-- it doesn't and you shouldn't expect it to-- then they say nitrate reducing media is "snake oil" after a week or few weeks. They don't understand that part of the cycle. Ammonia and nitrite removing bacteria can cycle in weeks, less if you seed your filter with some mature media. Nitrate reducing bacteria are more touchy, take months to "cycle", even though ammonia and nitrite are already cycled, and there are common practices that can short circuit them. Of course, there are other ways to get your tank to process nitrates than trying to get your filter to do it, plants, an algae scrubber, etc. (except DIY, algae scrubbers tend to be expensive from what I've seen)
Whatever the case, I run canisters, do large but longer interval water changes than some do, and I have low nitrates.
Whoops, almost forgot. I get fairly frequent power outages where I live. Several hours is nothing, overnight many times, 24 hours or longer not uncommon over the years, 10 days once (or was it 9) and longer than 2 days a few times. Unless it's hot weather, several hours, overnight, or 24 hours has never been an issue with my filters (more than a few hours and I used to run battery air pumps). I say 'used to' because after the 10 day experience (derecho, big storm) some years ago I bought a generator (looked for one during that outage but none were to be had).
Imo... or at least ime, except in hot weather a well maintained filter should be fine in an outage for up to 24 hours or longer. I've been through it many times, but that's me, I can't speak to everyone's filter or setup. The 10 day experience was hot weather, mid 90s, and I either flushed water through my filters (gravity feed) or took media out and put it directly in the tank-- near the battery operated air stones, which was actually pretty effective.
Imo... or at least ime, except in hot weather a well maintained filter should be fine in an outage for up to 24 hours or longer. I've been through it many times, but that's me, I can't speak to everyone's filter or setup. The 10 day experience was hot weather, mid 90s, and I either flushed water through my filters (gravity feed) or took media out and put it directly in the tank-- near the battery operated air stones, which was actually pretty effective.
