Hello. I have a 40 gallon AIO aqua top reef tank. I do have surface film. I purchased the Skim 350 Micro Surface Skimmer - Eheim. Had it for about 1 month and I cannot get this thing to start making micro bubbles. I tried using sponges, different heights and nothing works. Is there a better one to get where I won’t have to worry about micro bubbles that you guys had success with? I don’t have a sump

