How Long Will It Take To Cycle A Sponge Filter In A Cycled Tank?

[Sora]

I just got a small sponge filter for my 2.5 gallon quarantine tank. im cycling it in my already cycled tank. I know how long it takes in an uncycled tank, is it any different? thanks.

 

 

 

[Tommy Vercetti]

Much faster than an uncycled tank, as long as your Ph is not too low. I would say less than a week. But that is just a guess based on my 1 year with 7 aquariums.

Also you really don't need a cycled filter for a quarantine tank, in my opinion. I change water 50% daily in my quarantine tank and that works good for me.

Edited January 30, 2023 by Tommy Vercetti

[Lennie]

I would keep it at least 2 weeks in a cycled tank, and keep parameters in check in the qt tank for sure. Better safe than sorry. Med applications tire fish anyway,  and there is also the stress of changing place. You would not want it to deal with extra potential ammonia/nitrite damage., especially considering 2.5 is really small, anything may spike suddenly and may become harmful enough.

 

[jwcarlson]

I'd say a couple of weeks, but there's things you can do to speed that up.  

Re: needing a cycled sponge in QT tank, if you're doing big water changes daily, yeah you'll be OK.  But it also depends what you mean by QT.  If it's "my neon tetra has a white spot so I'm separating it" probably not a big deal.  If it's "I just bought 25 new fish and I'm slapping them in this 10 gallon for a few weeks to fatten them up and make sure they're not sick" then that might be more important.

That said... you can't necessarily make sure that the filter you have will have the right sized bacterial colony for wherever you are placing it.  I like them as a "jump start" but not a substitution for cycling.  Meaning, I consider every tank I set up a "fish-in" cycle regardless of how I set it up.  So monitor parameters daily if heavily stocked or every day or two if it's two small fish in a 55 kind of deal.  Water change a bit if things build up and when you start seeing "zeros" for ammonia and nitrite for a few tests you can be pretty sure your cycle is "done".  But, of course, it's never done done... as plants grow and fish grow/die/breed all of that changes things.  But an established bacterial colony can pretty quickly adjust do these things.

[Sora]

I think I will cycle it for a couple weeks, then put it in the quarantine tank. I have no problem doing daily water changes for such a small tank anyways. so I will probably be doing that. im planning on quarantining one betta in there to watch for sickness before it goes into my 20 gallon.            

[jwcarlson]

For that small of bioload you'll be fine as long as you're changing water fairly regularly.  I wouldn't necessarily bother trying to cycle the sponge completely anyway.  Doesn't hurt to let it seed from now until whenever you get the betta and just put it in when you get him.  When I first set up my 10 gallon QT I just had a 5 gallon bucket next to it with a heater and air stone in it and would change 50% twice a day.  Then as filters caught up a bit down to once a day.  Then eventually done with the daily ones.  It's very easy to stay on top of it even with big bio loads if you make the changes easy for yourself.  Now my QT tank is in with my aging/pre-heating barrels anyway, so changes are really easy.

[Sora]

okay!  thanks for your help