I have one pump at 7 cfm running three discs in the deepest and widest portion of my 1 acre pond. I have a big problem with chara thisw year due to low water levels this year. I would like to have two disc in the midle and one in the shallow entrance just too keep the water moving at least. That chara when it gets crazy really cuts off water movement. I have been manually removing it , and that helps a lot. I just think having more discs I could controll will make it easy for winter where I could shut off the deep end and use the shallows for keeping ice over. Guess I will use the obe pump for the deep and keep the other one for the shallows. I have really hard water so other then removing the chara by hand not much else seems to work.