I have a 10 pound tank coming my way with the rest of what I need to add CO2 to my tank. I have a 125 gallon tank that is 6 foot long. I thought I read somewhere here that it might be tough to distribute the CO2 across the tank evenly or something? Am I going to have such issues? Anything I can to do balance it out? Also ordered PMDD. Pumped about stepping up to the next level for my tanks plants. Hopefully this will help. Thanks!