My humble opinion is that keeping corals is easy and do not make it a science experiment. Looking at your early photos noticed your rock appeared "dirty". Please do not take that personally. When you see awesome SPS tanks, you see awesome coralline covered rock, without any "fuzz" all over it. When I see fuzzy rocks I think of not enough flow, not enough Blue Legs, no socks, too much feeding, etc. We all know SPS need pristine water and sometimes "fuzzy" rocks are good indicators of not so pristine water. The SPS in the photos are 100% guaranteed not dying from the vermetid snails. Noticed some of the frags you bought grew perfectly with the snails before you got them. My LFS has awesome Blue Tort colony, not frag, with vermetids as well. But having an outbreak of vermetids only reinforces the theory of "organically rich". Exactly the type of water SPS do not do well in. Are you adding phyto. If so STOP. The photos of your SPS also look like they are dying from a chemical inbalance. Are you adding too many supplements. All you need is Alk, Ca and Mg. The rest, stron., iod., amminos etc, are only to be used ones you have an awesome SPS tank and need the fine tune it. But I have seem many awesome SPS tanks with just the basic 3 being added. As far as Aiptasia nudis, they work. I have seen the ones from salty supply always work. Took 2-3 months but always worked. I suggest on the next tank, go sandless, as soon as it is cycled add a lot of sm blue Legs and a good amount of snails. Have good flow, or better great flow. Use sock ALWAYS. Use only basic supplements. GFO reactors, no problem. Change 25% of water every two weeks. Go see what your LFS does on their reef tanks. My LFS in Tampa grows and harvests SPS on a weekly basis. I would only listen to advise of people who grow SPS not people who repeat what they read. And stick to a plan. Do not go allover the place with RC advice. RC is awesome but it is million chefs.