I have a 125 gal aquarium. Im attempting a completely self-sustaining set-up. At least as possible as that is. I want to incorporate tridacnid clams as part of the eco system. I like the clams so was thinking to put 3 into the tank. One each of crocea, maxima, and derasa. Can a 125 gallon aquarium support 3 of these clams? My parameters right now are 0ppm nitrite, 0ppm nitrate, 0ppm ammonia. Calcium 400. Im experiencing hair algae, but got it under control with a Phos Ban system. Tried snails and hermit crabs, the hermit crabs ate all the snails and then the big hermit crabs ate all the smaller crabs. (I was also feeding the hermit crabs every other day with mysid shrimp and they ate all that too) I have 4 or 5 hermit crabs left right now. No other creatures at this point. The algae is still there, (they do eat it, but not enough) but not bad. Im sure when I introduce more animals they will take care of that. (Im hoping to put in 3 yellow tangs along with a few other types of tangs) I only have used dry rock in my aquarium at this point, because Im still working on the décor. Don't plan to get any more animals until Im done with the rock. Going to get some live rock once the major rock structure is done. Im moving slowly so that the biological growth in the tank is completely stabilized. I did seed the tank with copepods and amphipods. They are doing great. Plan to put in a brine shrimp hatchery for continual supply of live brine shrimp and also a hang-on refugium for extra filtration and live foods as well. Not sure which ones at this point. (thought I would also start a population of larger live shrimp in the main tank as well). I have an auto-refill tank so my salinity stays right at 1.025 with no fluctuation. I haven't installed a kalwasser yet, but I'm using limestone base rock for the rock structure (hoping this will release calcium into the water). Plan to put in mostly peaceful corals, montipora, etc. (anything that won't try to kill or injure its neighbors) Really don't want to deal with a kalkwasser unit if I can get away with it. I plan to have chromis, tangs, and other assorted reef friendly type fishes (non aggressive). No angels because they bother the clams. This is my plan. Question is : Is my tank going to be able to support 3 tridacnid clams once they start to get bigger? Also, do I need to set them on a flat piece of stone for a permanent attachment or will the sand bottom do the job? They won't attach to the glass will they? Don't want to hurt them if we have to move them in 5 years. Would like to set them up right the first time. Thanks for some info.