I can't afford an ISO tank. All the stores like Walmart (probably the cheapest place around) the cheapest tank they have is 2.5 gallons and $20! I was thinking of using my main tank as ISO (10g) and lean toward getting a 20g for my main tank but all the stores in my area are way too expensive. And there are no flea markets around whatsoever. Does anyone know of a store that has lowpriced tanks?