how about that rena xp3 on my 30 gallon? does anyone know if i can control the flow rate just incase its too powerful..... i have a 4inch JD with a 7inch pleco... i don't wqant the xp1 or xp2 because i can get the xp3 for the same price.... therefore, i was hoping the xp3 wouldnt be a problem in the 30gallon.... any1 got any advice? i compared rena and fluval and decided to go with the renas instead of the fluval. So can any1 help me?