My neon green candy cane coral is doing the same thing. I just did a water change using the store bought already mixed ocean water. My calcium is at 450, alk was low and I just adjusted it. Alk was reading 7, nitrate and nitrites are 0. Phosphate pre water change was a little past 0.25ppm. I don’t have a magnesium tester yet. Previously my corals were on the left side with a lot of light. Came home today to two dead tangs and cloudy water. My rhodactis died. Here are photos any suggestions? I also had an issue with cyano but I treated that and the issue was resolved.
Your tank looks brand new/very young. I wouldn’t put LPS in a tank that isn’t at least a few months old (especially if you’re not experienced). You don’t want to change your alk suddenly, you want to slowly change it over time, sudden changes can be deadly for stony corals. Also, an alk of 7 is just fine (that’s where natura sea water is at), you don’t want to go lower, but it’s not a problem. Whatever your alk is, so long as it’s within range (7-12), is not that important (its posited that higher alk leads to faster growth), the important thing is stability, pick a number and stay with it (personally I would pick a salt that mixes to where you want your alk and then just maintain it. Also, if your tank is new, you shouldn’t have 0 nitrates, either it isn’t cycled or your test is wrong. If it is cycled and it’s truly zero, that’s an issue, you want some nitrates (ideally 3-10ppm, less or on the lower end of that scale if it’s an sps dominant tank).
Again, your tank looks very new, too new for LPS and two tangs. You likely had a bacterial bloom (cloudy water) because your tank is still cycling (might be processing ammonia, though your nitrates are zero, so that says to me that it isn’t). The bacterial bloom used up all the oxygen in the tank and your fish asphyxiated.
If your Rhodactis died, there is something very wrong with your parameters, they are very hardy and withstand a lot. I recently set up a tank in Jan, and had a Rhodactis in it from day one, I wouldn’t recommend people do that, and normally I wouldn’t either, but my lfs wanted me to test out this new bottled bac they started carrying (aqua vitro seed), so they gave me a free (quite pretty) Rhodactis to see if the bottled bac was as good as advertised (it wasn’t). The mushroom is still alive and doing great, never worried about it once.
I would really work on maintaining stable parameters and not add any new livestock until they’ve been stable for a month or so, and then add things slowly, and for corals add some softies first and if they do well, then try some LPS.
As far as your candycane is concerned, it doesn’t look good. If your tank was established and mature, there be a good chance that it’d recover, but in an unstable tank its very unlikely to recover.
