take a pic of how it's set up in the sump, if you can...
but, the things that i would suggest would be to restrict the air inlets with valves, and to make sure the gave valve outlet is above the water level in the sump, and, an iwaki 55 isnt enough...you need i'd say at least 900gph feeding each injector, so i would suggest a 1800-2000 gph pump with a valve on it for adjustment, or like 2 smaller pumps, one feeding each injector.
i even had a rio 3100 (950 gph) feeding my reef devil and i didnt have to throttle it back at all, and the entire reaction chamber was filled with foam, no visible water line...
another thing i did to increase performance was to take out all the lame ass bio balls it comes with, and replace with some i had lying around that had 1/2 the thickness of needles on it, as well as the needles being more numerous,
and they were diamond shape, not round.they had little male and female parts on the top and bottom so you could stick them together if you wanted, i'll try to see if i can find a pic online of the ones im talking about, they were very large bio balls that took up almost the entire space of the downdraft injector, and, i only had 2 of them in the bottom, that's right, only 2.
massively better performance than stock.....
