How Long Can A Fish Survive Without Filter

[qieter]

Hi,

My fluval 304 is still not working and I want to know how long can my trimac pair and their fries survive without a canister filter if i change 25% their water every day??

Vic

 

[ChilDawg]

How large is the tank? You'll need to get a filter for Trimacs pretty quickly no matter the tank size, but they could survive for a day or two in, say, a 300.

 

[OrionGirl]

Is there anything in there providing water movement? That will be important, since the oxygen in the water is replenished via surface agitation, usually from water returns or movement through filters.

Rather than randomly changing 25%, the better solution is to test the water and do changes large enough to keep the ammonia and nitrates as close to 0 as possible. While the filter contains most of the bacteria, all the solid surfaces in the tank will house some bacteria. These populations will expand to take up the slack, but this will be a slow process (days or weeks), so big water changes will be best.

If you didn't have the fry, I'd say to drop the temp and quit feeding, but that won't work here. You can lower the temp a bit, but reducing feedings might result in the loss of some fry, depending on how old they are now.

 

[qieter]

I have increased the rate of the two airstones to the max and the fries are only about a week old....and ill be getting a new filter today ...they have been without filter for about 12 hours....hope they ll be fine..

vic

 

[OrionGirl]

12 hours should be okay with the steps you've taken. If you can, save the media from your current filter by rinsing it gently and soaking it in the tank. This will also help keep the ammonia/nitrites from getting as out of hand.

And here I thought you expected to keep it running for 4-5 DAYS without a filter!

 

[Slappy*McFish]

I've had sensitive fish survive a winter power outage for days with no filtration, aeration, and the water temperature hanging around 50F. But things do tend to "slow down" at that temperature, however.
Granted the tank isn't over-stocked, you are providing aeration and water changes, the fish could live indefinetly without filtration... as the bulk of the nitrifying bacteria live in the tank itself, not the filter.

 

[RTR]

Slappy, if you make blanket statements like that, it might be better to provide references or some justification, as there are a number of folks here who disagree with that statement very strongly.

 

[Slappy*McFish]

RTR, I'm sure there are certain filters that DO contain a large part of the bio-filtration..namely wetdry and some canister filters...but in a well established tank with plenty of interior surface area(ie, rocks, gravel, driftwood. etc) there is plenty of bacteria to support a moderate to understocked tank. Notice in my original statement I gave certain conditions...not overstocked, aeration, with water changes, etc. I have kept tanks without filters before with no ill effects..and when I clean my filters, I usually just blast them under the tap with no real damage to the overall bio capacity of the tank...even my canister filter...no ammonia spikes, nothing. I have no "documented" data to support my claim, just personal experience.

 

[RTR]

It is even possible to operate tanks without filters at all (either as per Diana Waldstad, or with calibrated automatic changers). Neither of those are novice techniques.

But in most tanks the nitrification bacteria will colonize where the food and oxygen supply is optimum, and that is normally in the filters - providing both, constantly present and constanly renewed with the maximum flow in the system.

If that is not the colonization site it due to operator handling which destroys or reduces developing colonies and so prevents their maturation. And that message was not in your post - which to me at least is misleading, as it is not conventional handling. It is not wrong, it is just not usual and to me should be noted and explained.

Thanks for the clarification.

 

[Canuck]

But in most tanks the nitrification bacteria will colonize where the food and oxygen supply is optimum

I'm curious about this. Why would the food and oxygen be optimum in the filter. The food supply should be no greater inside the filter then in the area around the filter inflow or outflow, same oxygen content, same food content. Most filters take water from the lowest parts of the aquarium, which I believe should contain the lowest levels of dissolved oxygen, if most of the oxygen is dissolved from surface agitation. (Of course this would not be true necessarily in the case of a wet dry system). But most filters especially HOBs require regular maintenance, disturbing if not killing many of the nitrifying bacteria, this of course limits the size of the potential biological activity. Many people seem to overfilter there tanks, this again limits the effectiveness of the filters biologically. Turning the water over say 10X an hour puts more oxygen in the system making the tank itself the stable colony for nitrifying bacteria, higher oxygen content and less disturbance.

My experience (with moderate to low stocking levels) coincides with Slappy's. Filters seem to provide excellent mechanical filtration and good water circulation that even after a stringent cleaning have no effect on the nitrification cycle. My experience would also seem to suggest that with a moderately stocked MATURE tank, gravel and decorations provide more then enough sites for biological activity. There will only be X amount of ammonia and nitrite in any system that supports X amount of bacteria. Many filters provide lots of area for development of bacteria but I'm not sure that these are going to necessarily attract the majority of the bacteria.

Don't mean to step on any toes, I'm just curious to hear your rationale.

Respectfully,
Dave