tyler_hobbyist, You know when You are trying to put too much air into Your reservoir when it blows out all of the water! LOL . No, seriously now, I use an Elemental 127 GPH dual outlet pump (about $10 and a one year warrantee) with two 4 inch air stones in a six gallon reservoir (actual sixe 10 gallon tote). Keeping the water temperature below 70 deg F. and well aerated, are very important to having a healthy environment for your roots