How to start a Planted Nano Tank? Planted nano tank are small tank (usually less than 5 gallons) that are relatively easy to start up. These tanks are perfect for someone who is starting with fish tanks, or for someone who does not have a lot of space, time or money to maintain a larger tank. Planted nano tank can range in size from 12 oz. (Beta bowls) all the way up to 5 gallons."Planted Nano Tank- How to Start an aquascaping planted nano tank?"