Empty Tank Question

[mikey11]

I have a healthy tank that is mature/cycled has been for 5+ years,

Without going into a long explanation as to why.....I will be removing all of the fish from this tank and the tank will be without fish for a couple of weeks....filters will remain and be running.....

so my question is.....will the bacteria be okay and survive all that time without fish in the tank?....will the tank remain "cycled"?

 

[kornel351]

I would put ammonia in the water just ti make sure

 

[Essjay]

The filter bacteria do live a long time even without food, though the longer the duration the more that will become dormant. The fishless cycling method on here recommends that if fish cannot be bought as soon as the cycle is finished, the bacteria should be fed by adding 1 ppm ammonia every 2 or 3 days. That will work just as well with your tank. You don't need to add a lot of ammonia every day.

 

[Byron]

I would not recommend adding any ammonia. You risk killing off various bacteria if you should add too much. An aquarium that has been running with fish for five years will have all sorts of different bacteria, primarily in the substrate, but also the filter.

My QT for new fish acquisitions can sit fish-less for months, and then 20 and more fish may be added together. I have never had issues. It does have live plants though, which also helps. Do yo have any live plants?

 

[mikey11]

I would not recommend adding any ammonia. You risk killing off various bacteria if you should add too much. An aquarium that has been running with fish for five years will have all sorts of different bacteria, primarily in the substrate, but also the filter.

My QT for new fish acquisitions can sit fish-less for months, and then 20 and more fish may be added together. I have never had issues. It does have live plants though, which also helps. Do yo have any live plants?

it is a "bare bottom" tank....it has nothing in it except for filters and heaters, that is all....

i breed angelfish, and this is a holding/growing out tank, it is a 100 gallon tank and normally has anywhere from 100-200 nickel to quarter sized angelfish, but for the first time ever it will not have any fish in it for 2-4 weeks, i just sold off a big batch of fish earlier then anticipated, and won't have more to put in there for 2-4 weeks.....

i keep it "bare" because its easier to keep it clean and healthy for them,

it has one aquaclear 500 filter with 2 sponge/foam inserts in it....and three large air powered sponge/foam filters, which are all mature media

 

[Byron]

it is a "bare bottom" tank....it has nothing in it except for filters and heaters, that is all....

i breed angelfish, and this is a holding/growing out tank, it is a 100 gallon tank and normally has anywhere from 100-200 nickel to quarter sized angelfish, but for the first time ever it will not have any fish in it for 2-4 weeks, i just sold off a big batch of fish earlier then anticipated, and won't have more to put in there for 2-4 weeks.....

i keep it "bare" because its easier to keep it clean and healthy for them,

it has one aquaclear 500 filter with 2 sponge inserts in it....and three large air powered sponge/foam filters, which are all mature media

This is a very different situation. When the fry are present, I would expect you do several significant water changes per week. I would want to monitor ammonia and nitrite if this were me, though I would have floating plants covering the surface which would eliminate any likelihood of either. [I am a great believer in floating plants no matter the tank. ] And of course without a substrate you have other issues that water changes will benefit.