Hey everyone,

I have been pretty busy with non-goldfish related matters so I haven't been here in a while now.

Anyway I'm thinking of getting a bigger planted tank (90g or so) and turning my current 55g planted tank in a goldfish tank.
Right now I have one oranda (about 3-3.5" big) in a 10g. I am hoping to move him to a bigger tank eventually.

First a couple of questions:

Filtration: Right now I have an aquaclear 50 HOB and aquaclear 20 HOB for my 10g where my oranda li
es. It is bare bottom and I have zero poop build-up. Of course this will not be enough for a 55g, so I was wondering if one aquaclear 70 HOB + AC20 + a small powerhead (located on the bottom to keep poop from collecting) will be good enough.
I will then use the AC50 for the 20g tank I swapped the AC70 from.

# of goldfish: I would like to add more fancy goldfish, how many would be good for a 55g? 3-4 orandas?


So basically 1 AC70, 1 AC20 + small powerhead in a bare bottom tank, then with a with hardy plants that are either floating or potted and some garden clay pots for "caves" for the goldfish.
For lighting it will be a retrofitted DIY 2x normal output T12 light box, so about 80watts.

Well the generally used rule-of-thumb is 100x turnover per gallon. 55 gallons = 550 GPH. The AC07 is only 300 GPH and the AC20 is 100 GPH = 400 GPH. When we're talking about BIG fish in large numbers, the more GPH the better. For 4-5 big orandas in a 55gal, I would shoot for at least 600 GPH. How much output would the powerhead + sponge prefilter give you?

Perhaps a better idea would be your AC50 + an AC70 + powerhead. That's at least 500 GPH.

On the other hand, if you keep the tank understocked (less than 5 goldies), a little less filtration may get you by.

As for how many fish, it really depends on your filtration and the size of the fish. Big fish need more room, period. However, small fish get big.

Hope that was helpful.

I have 630 turn over in my 55 with 5 goldies I change the water every 3 days ..I don't have too ..but I like too..and I have lots of biomedia in my filters..I think 4-5 will be fine I have also pushed the limits at 6 once and did not have issues as long as your willing to do the work on your part

Thanks! I will keep this in mind when I upgrade.