Before we say get a 10g or 5g,, how much room do you have to grow in.. can you use a 3G pot a 5 g pot? I stop at 3G for soil and 5G for DWC because of space. So if you have room.. more then 1.5 will be needed. Also more room = bigger plant = bigger pot needed. If your a CLF dresser grow1.5-2.5 will get you done.