Hi everyone its been awhile since i've been on here. I currently have a goldfish in its own 10+ gallon tank and a betta in his small tank. I want to get my Betta a slightly bigger tank I saw a aqua one cube 30 tank which was roughly 30cmx30cmx30cm does anyone know how many litres or gallons that would hold?

about 27 litres = about 7 1/2 gallons

Thanks I think I might buy it for him. He is currently in a 12 litre tank which is about 2 gals.

12 litres is 3 gals