New Tank Setup Diagram

Far too small for three goldfish IMHO. And a sponge filter really wont get the mech filtration that you would want with goldies as they are relatively large waste producers. I would go with a HOB in conjunction with the RUGF, but again you will really need a larger tank.

Just once see the diagram :)

Have an UGF in conjunction with internal power filter and sponge filter
 
Sorry, missed the power filter part...anyways no amount of filtration will keep up with three 8-10" goldfish (that could end up being an underestimate) in 15 gallons worth of space.

Total length of all the fishes is 6.5 inches(1.5 inches for two orandas each and 2.5 inch for shubunkin)
 
A very general rule is 30 gallons for the first goldfish and 10-15 (I've heard several different views on this) gallons for each extra goldfish. According to that you would be in the 50-60 gallon range, which seems appropriate to me. I would try at least a 4 foot tank which would be something like a 55g or a 75g.
 
A very general rule is 30 gallons for the first goldfish and 10-15 (I've heard several different views on this) gallons for each extra goldfish. According to that you would be in the 50-60 gallon range, which seems appropriate to me. I would try at least a 4 foot tank which would be something like a 55g or a 75g.

Okay :)
 
IF ur on a budget, u can wait for petcos $1 per gallon sale and get a 55G for $55:)
 
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