For a Fantail Goldfish you will need at least a 29-40g tank. Start looking at $1 per gallon sales or used to save money.
A Pleco ? Commons need about 125g
The Oto can stay in a 10g, I'd add 1-2 more Otos.
Zebra Danios ? 20g Long minimum...very active swimmers and hit 2.5-3"
Please research each of your fish and you'll see where I'm getting these tank sizes.
It's a great hobby !
This is an old thread, but lots of great GF info
Why fancy goldfish require big tanks- visual perspective
Also Solid Gold on YouTube has great GF vids with excellent tips.
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