Have had this skimmer of my forty gal reef for a few months. I was not particularly pleased with the performance because I had seen other ASM skimmers that produce finer bubbles and more of them. This was disappointing because I did my research and I wanted the Turbofloater skimmer but the store sales guy talked me into the ASM product. The reviews on the Turbofloater were excellent but he said: "that he had had both and the Turbo was much more difficult to keep adjusted". Ironically after having the ASM for a few months it was the ability to make adjustments that I was missing. I don't blame the sales guy, I don't know if the one he had owned was the Baby G or not, and every model works slightly differently, plus they are always changing the pumps that they sell them with. As with most ASM Skimmers there is no airflow adjustment, just one tube that allows the same amount of air into the chamber consistently. The standpipe adjustment does little if anything to increase the amount of air in the chamber. It may have an affect on the dwell time for the bubbles (hard to estimate). For the most part it only affects the quality of the foam it produces by either raising or lowering the water level at the top of the skimmer. I decided to try putting a balsawood airstone in the chamber to introduce more air. I bought the cheapest pump I could find, $6.99 and 4ft of air line and the airstone. I then used a hot knife to slice a groove in the top of the skimmer lid to accommodate the air line. I placed the airstone (wood) into a small glass bottle (previously a spice container) and strapped a rubber band from the bottom of the bottle over the top to prevent the airstone from coming out. I used the glass bottle to weigh the airstone down. Otherwise it floats to the top of the chamber and the whole purpose is to give the bubbles dwell time, so you don't want it at the top. You could use anything, obviously you wouldn't want to use any kind of metal that would oxidize in your water. Ideally you would have something made of glass that is small and heavy, but the spice jar was all I had and it worked well. At first I was afraid that the bubbles would mass in the bottle and form larger ones. I tested it in the sump before putting it into the skimmer and this was not the case. I dropped the whole thing down through the collection cup to the bottom of the chamber. It immediately doubled the amount of bubbles in the chamber and I could immediately notice improvements in the amount of foam
in the collection cup. I was concerned that the small bottle may take up space in bottom of the skimmer and affect performance, but not so. In fact the bottle serves as a little chamber in it self at the bottom of the big chamber a large mass of fine bubbles pouring out of it every second. It has been days since I made this improvement and the skimmer is working much better now. Besides a little extra power consumption cost, this mod cost me less than $15 bucks and has improved the performance by at least 30% by conservative estimates. I would highly recommend it to anyone who is not satisfied with the performance of their ASM Skimmer, it should work with all models. If it doesn't work out then the most you will be out is $15 bucks, but based on my results it is an affective modification.