Keeping an empty tank cycled?

[daisycat]

We are due to get our substrate for the 400L tank today - woo! Once it has cycled we're moving everthing out of the 30g into that one and adding some more small fish as time goes by.

We want to keep the 30g running so we can use it as a quarantine for the new fish/hospital tank/future breeding tank but do we need to do something to keep it cycled? - Surely if no fish in there then the cycle will break down and we will need to recycle it everytime we want to use it, which seems a bit pointless, especially in the event of a sick fish emergency.

The 30g is out in our garage so I feel kind of mean about putting fish in it to keep the cycle going - but is this what we should do? If so, what fish? And won't they be threatened by any ill fish/new fish etc we put in there.

Confused!

 

[Angry_Platy]

I am assuming you have separate filters for both tanks....

If so...keep the filter for the smaller tank running on the larger tank...then when you have a fish emeergency all you need to do is transfer the filter across to the smaller tank and it is ready to go....cycled and all....

Myself, I leave water in the quar tank....then when it comes time to use it I remove about 30% of the water and replace it with fresh stuff....put the filter on and it is instantly ready for sick/new fish

 

[daisycat]

Yes, we have separate filters.

That is an interesting option that I hadn't thought of! Thanks for the suggestion.

 

[tstenback]

the other thing to do if you dont have room for both filters on the one tank is to add ammonia to the tank daily as it is the ammonia that keeps the cycle going. HTH

 

[daisycat]

I had read about that tstenback but the place where I get ammonia from is hard to get to so was hoping to avoid if possible...don't want to make a rod for my own back, if you see what I mean!

Fortunately our new tank has ample space for several filters and we were planning on getting a second filter anyway as our turtle is a dirty little thing and the tank really needs a lot more filtration than if just keeping fish.

 

[tstenback]

THe filter idea is the best option anyway and in this case with the extenuating circumstances it is the only option. Good Luck