How turning off filter affects good bacteria?

[ArkD'Julie]

A couple times a day for a couple hours at a time, I turn off the filter on the tank with my betta (also neons, peppered cories, and a bristlenose cat) in order to give him a break from the water current. Usually, if it's not already on, I turn on the airstone then.

Is turning the filter off for short periods (even overnight?) too detrimental for the good bacteria, or is it ok. If this is ok, what amount of time would be detrimental to have the filter off?

And, I just want to say that I've been reading many of the older threads and replies and have already learned lots. I really appreciate that there are so many people who enjoy their fishies and are willing to (and enjoy) passing on their knowledge to newbies like me. I am really involved in training my dogs and I know that when I occasionally help instruct students at my local dog club, it feels really good to help them.

Julie (I'll try to get a signature put together soon)

[FishyPastor]

In my own experience s long as the filter media is kept wet it should be fine. I have done so when my filters broke down. I would more water changes if its off for days though.

[Cliff]

I would suggest you leave your filters on all the time, unless you are cleaning it or the tank

You have to keep in mind, when you turn off your filter, the tank water is not reaching your biological filtration and ammonia could start to build up in the water

If you forget to turn it back on one day and it is off for about 24hours, your BB will start to die off

Yous fish should not need a break from the current, they will be fine with the filter on 24/7

[Goes to 11!]

I would suggest you leave your filters on all the time, unless you are cleaning it or the tank

Yous fish should not need a break from the current, they will be fine with the filter on 24/7

+1

It's a 20+g tank & they have plenty of hiding spots where the flow is decreased, Unless you're filter turnover is massive [+20xhour] It's a non issue. Let it run.

[DrNic]

In the absence of moving water the bacteria in your filter will stay alive for about 72 hours or so depending on the temperature in the room/water. During this time however a series of events occurs. First the bacteria continue to divide and eventually become crowded in the media without any water flow (normally they would just get flushed into the tank). Now that there are 'extra' bacteria in the media there is more competition for nutrients. Since there is no water flow however there are less nutrients available and some of the bacteria begin to starve and eventually die. The remains of these dead bacteria then begin to act as toxins and kill the remaining live bacteria. If left long enough, even when wet, all the bacteria will simply die. It's important to note that these dead bacteria can also act as toxins to fish in the tank. This is why after blackouts of more than 2 days it's advised that you rinse out your filter and media before turning it back on.

Overall I would leave your filter on all the time if possible. If you feel that there is too much flow coming out think about adding a diffuser to the output. Sometimes just a piece of filter media on the output can reduce the water flow enough to help out the fish.

[funkman262]

DrNic, do you have the publication where that info and numbers came from? Dead bacteria actually serve as food for other bacteria. As bacteria die, they release nutrients which can then be taken by growing bacteria which allows them to survive periods of time in nutrient-deprived waters. What chemical exactly acts as the toxin? These bacteria are quite resilient. They thrive pretty well in aerated wastewater and think of all of the chemicals and such that are in there. Aside from the concentrated organics within the water, the ammonia can be upwards of 20ppm but they don't die off quicker than they grow.

[Lady Hobbs]

I would not turn those filters off. They are meant to run 24/7. And way too easy to forget turning them back on.

[jetajockey]

DrNic, do you have the publication where that info and numbers came from? Dead bacteria actually serve as food for other bacteria. As bacteria die, they release nutrients which can then be taken by growing bacteria which allows them to survive periods of time in nutrient-deprived waters. What chemical exactly acts as the toxin? These bacteria are quite resilient. They thrive pretty well in aerated wastewater and think of all of the chemicals and such that are in there. Aside from the concentrated organics within the water, the ammonia can be upwards of 20ppm but they don't die off quicker than they grow.

While I'm interested to hear the answers to your line of questioning I did want to address the little bit I do know about nitrifying bacteria. In the studies I've read, the nitrifiers in home aquaria are not the same species as the kind found in wastewater treatment plants. This is part of the reason why most of the big name bacteria-in-a-bottle products work temporarily at best. There was an assumption that you could just get nitrobacter from anywhere and throw it in and solve the problem. It's more complicated than that though.

I do know that with fishless cycling, having concentrations of ammonia over 4-5ppm will begin to slow down the process.

I don't know about the science behind those other statements.

This is from personal experience, so it's far from objective. I've kept canisters off for a week during a move and after a quick rinse they kept a cycle. There is also a good amount of nitrifying bacteria in the tank as well, it's just not as concentrated as it is in the filter area. I bought a bowfront last year that was dried out for at least a week, filter completely cleaned and dried, and the sand substrate was in a bucket and was just a bit damp. Added it all back to the tank when I set it up, and even with daily testing, never experienced an ammonia or nitrite spike, so that says something to me about how much bacteria the substrate can have on it also.



Back to the OP. If you are running a HOB did you try maybe a simple diffuser? I don't think it's a huge deal to turn off the filter for a few hours a day, in other countries where electricity is more of a luxury, it's very common for them to turn off things like aquarium filters overnight to save money.

I wouldn't even bother with a air bubbler unless its for aesthetic value, in the few hours that the tank doesn't have the filter running, it is not going to drop the o2 to any extreme level, plus anabantids are equipped to deal with it in the event that it does.

[funkman262]

While I'm interested to hear the answers to your line of questioning I did want to address the little bit I do know about nitrifying bacteria. In the studies I've read, the nitrifiers in home aquaria are not the same species as the kind found in wastewater treatment plants. This is part of the reason why most of the big name bacteria-in-a-bottle products work temporarily at best. There was an assumption that you could just get nitrobacter from anywhere and throw it in and solve the problem. It's more complicated than that though.

You're right in that it was believed at one time that nitrobacter was the main nitrite-oxidizer in wastewater treatment, however that has been proven incorrect. In fact, nitrosomonas and nitrospira are the primary ammonia- and nitrite-oxidizers, respectively, in both wastewater treatment plants and home aquaria. Sorry to bring up this information but as a graduate student in environmental engineering I've learned much about the microbiology and chemistry in wastewater as well as freshwater and marine systems so I try to correct misinformation when I can.

[jetajockey]

The input is much appreciated. It seems like it's hard to find data that isn't agenda-motivated (i.e. product sales) or based heavily on speculation, so any type of real scientific insight is refreshing.