I coudn’t See doing 700 + gph as that would almost be 10 times turnover just on the return pump. I am using a Sicce 9.0 SDC and it makes around 600 gph at full speed but I am running the return at around 450 right now and running 2 WAV power heads at around 10% each LOL. Those WAV pumps are no joke they kick up sand even at 10% sometimes.