Suggestion for permanent fish in a nursery tank

[Toadkitty]

Our bristlenose plecos, cory cats, and zebra danios have all begun breeding recently. When the cories and danios laid eggs we didn’t have a spare tank to move them to, so they didn’t last long. Since then we’ve been given a 2.5 gallon tank that we’ve deemed the nursery.

We plan to move eggs/babies to the nursery until they’re big enough for new homes (there are baby bristles in there currently), but since we’re not sure when eggs will be laid (we do nothing to induce breeding, it seems to happen at random), we don’t know if the tank tank will be empty for weeks, months, or maybe even a year. We’d like to keep it cycled so it’s always available.

Which leads me to my ultimate question, should we keep fish in the tank as permanent resident(s) to keep it cycled? If so, what would be appropriate for such a small tank?

Thank you for any suggestions!

[Aiken Drum]

I wouldnt keep fish permanently in a 2.5g tank.

I have a 2.5g tank for similar purposes, keep it in a cupboard when not is use. When i use it, I just take 8ish pieces of filter media from a canister, drop into the 2.5g filter. Instant cycle.

[Autumnsky]

2.5G although fish fry are small a 10G , and usually more like a 20G is better.

Reasons being due to having to feed frequently like 3-5 times a day pollutes water fast and can ruin water quality in a 2.5G whereas, a 10-20G gives you more room for growth and more time for doing big water changes since you have more water volume.

Fish can produce hormones, and while growing with a minimal amount of water it can stunt growth. Opposite of what you are striving for.

The instant cycle above is a perfect thing to do. If you have a filter pad you can hang in a cycled tank under the outflow of a HOB/ hang on back filter. Grab it out and use it when you need it. I used to have a bag (from the produce department which held Onions, garlic or lemons) which held a big bag of ceramic filter media just for any old group of fish I might end up with!