Pea puffers need a 5-gallon tank as a minimum. A 5-gallon tank can typically only house one pea puffer. Despite being small, pea puffers require plenty of space to accommodate their active lifestyle.
To keep multiple pea puffers, the first pea puffer requires five gallons of water and each additional puffer needs three gallons of extra water. Therefore, if you want to keep two or three pea puffers, you’ll need a 10-gallon tank or bigger.
Keep in mind that if you want to breed your pea puffers, you’ll need a bigger tank. A 20-gallon tank is a minimum for a breeding setup. It should be enough to house a male pea puffer and up to three female pea puffers.