I'm not sure if this is dependent on species or not, but have seen it noted many times that Octopuses prefer a low flow. At the moment I have a relatively low powered return pump, which I want to increase to have more movement through the sump. I'm at about 164gph now after head loss and as my tank is 55 gallon, I should be at least at 250. I also have two powerheads, both Koralia, one 850gph and one 1150gph. These will not be on during the night and will be on 30 second intervals during the day. Will this setup be OK for an octopus? I want to make sure I don't have too much flow as I want to create the best environment possible. Thank you.