another possible issue you are having is related to the tubestrea. Your other corals may be upset that you are having to disturb things to feed it so much (they do need feedings at least every other day). I think you are very brave for trying tubestrea in a tank this size, largely because they are nonphotosynthetic, and require you to feed them often enough that it could easily pollute the system water in a tank under 10 gallons. It seems like you researched the critter before you brought it home though, and I bet you'll do fine with it. Would love to see pics! Tubestrea is one of my favorite corals. I'm planning to add an orange one to my 75 soon.
J.
J.