I am getting a bigger aquarium, have a question.

[Obsessed with fish]

I measured my tank wrong, I thought it was 25 gallons, I measured it again and it is actually 15 gallons! I have sterbai corydoras (and other fish that are ok in the 15 gallon), a 15 gallon is not big enough for the corydoras. The poor corydoras have been stuck in this thing for years! I asked my mother if I could get a bigger aquarium, she said yes, as long as I pay for everything. I am going to try get one for free or very cheap off Facebook marketplace.

Now, my current tank is very well established and has two filters, lots of plants, driftwood and rock. My question is, will I have to cycle the new tank, or can I just add the stuff from my old aquarium to the new one. I have 4 neon tetras, 5 sterbai corydoras, 3 otos and two honey gouramis. I am not planning to add additional fish to the new tank, just my old fish. Will I need to cycle the new one first? I will probably get a 20-30 gallon. Thanks in advance!

 

[GaryE]

Is it your plan to keep both tanks, or shut the 15?

If it's the latter, transfer everything over while it's all wet, and you're good.

Here's a wrinkle. A 20 gallon and a 15 gallon standard tank have the same footprint - the same base dimensions. That's all that matters to a Corydoras, so the extra 5 gallons will mean nothing to them. It won't be an improvement. You may get a tank that is 30 or 36 inches across the front, and maybe the same front to back dimensions. That would be fine.
I don't think a 24 inch 15 gallon is an awful home for Corys. A cube 15 would be very small. A 30 gallon would give them room to run a little, but if they have done well for years, you are ahead of most young aquarists. They would seem to have a good home.

 

[Obsessed with fish]

Is it your plan to keep both tanks, or shut the 15?

If it's the latter, transfer everything over while it's all wet, and you're good.

Here's a wrinkle. A 20 gallon and a 15 gallon standard tank have the same footprint - the same base dimensions. That's all that matters to a Corydoras, so the extra 5 gallons will mean nothing to them. It won't be an improvement. You may get a tank that is 30 or 36 inches across the front, and maybe the same front to back dimensions. That would be fine.
I don't think a 24 inch 15 gallon is an awful home for Corys. A cube 15 would be very small. A 30 gallon would give them room to run a little, but if they have done well for years, you are ahead of most young aquarists. They would seem to have a good home.

The 15 is very tall, thanks for your help!

 

[GaryE]

Ah. I hate tall tanks.

If you transfer everything and use treated water for chloramines/chlorine, your cycle will be intact. It'll probably be cloudy for a bit, but will work out.

 

[sharkweek178]

The established filter media is by far the most important thing to transfer to maintain the cycle. Is your current filter rated for the larger tank size?
I find that adding some fast growing floating plants can help with any hiccups in water quality. Plus the honey gouramis will like them for shelter.

 

[Obsessed with fish]

The established filter media is by far the most important thing to transfer to maintain the cycle. Is your current filter rated for the larger tank size?
I find that adding some fast growing floating plants can help with any hiccups in water quality. Plus the honey gouramis will like them for shelter.

One of the filters is rated 15 gallons, the other one is rated 10 gallons. So I think there will be enough filtration. I have tons of hornwort. Thank you!

 

[sharkweek178]

One of the filters is rated 15 gallons, the other one is rated 10 gallons. So I think there will be enough filtration. I have tons of hornwort. Thank you!

There are two kinds of fish keepers. Those who have no hornwort and those who have tons of hornwort.