Filter feeders and seahorses

[cstephan]

My first love in the hobby is sea horses. I've kept them for many years off and on as time has permitted. A friend recently gave me a 125 tall tank with lots of rock and a sandy crushed coral bottom. He was using it solely for fish. I converted it over for sea horses. I added a 40 gallon sump/refugium and took some time to build a hardy amphipood/copopod population, and add booster lots monthly. I have some pipes and a mated pair of red mandarins. I also two pairs of sea horses and all are plump and happy. But unlike my experiences in the past I am not doing so well with filter feeders, which I love almost as much as sea horses. I have lost several gorgonia and am watching my orange tree sponge get smaller and smaller. Even my feather dusters are not thriving. I feed them many different live micro alges and phytos and decapsulated brine eggs but they still are not doing well. They are open and seem to be feeding. I have adjusted the flow but it does not seem to help much. I thought I would be able to keep these animals with all the great foods available now but it's obvious I need some help. Could it be the size and shape of the tank? I also use a protein skimmer, but I keep it off for 6 hours after I feed. Any ideas or thoughts would be appreciated.