HELP!! Im losing my Acan!

[zum14]

OK so i will try to attach pics(when i find a post that tells me how) i seem to have terrible luck with it. Ok so april 14 i noticed my acan wasn't fully inflated as normal and tentacles wernt out.. didn't think too much of it, just figured a crab or shrimp just went over it but continued to monitor, same yesterday, then today, its terrible, im seeing white on it and it doesnt look good. I dont really get why, it was starting to grow, all other corals are growing great (frogspawn, acropora, montipora, zoas, shrooms, xenia ) Nothing is close enough to take it out. Water perameters are as follows.

Salinity 1.0248
Ammonia unreadable
Nitrites unreadable
Nitrates unreadable
Phosphates Less then .25 but not 0
dKh 13
Calcium 420ppm
Ph 8.2

I do weekly 5% water changes, was due for one today but havent done it yet. Would really love to save him as i havent lost anything yet but fear hes too far gone. Any help would be great. Thanks.

[zum14]

So the first pic is April 14 and the second is this morning. Im off for the next 4 days so if i have to dip this guy every 15 mins i will do what it takes, hopefully all is not lost.

[whatcaneyedo]

If there is an infected area of necrotic tissue is generally works to blast it off with a turkey baster into a separate bucket of water... it doesnt really look that way in the picture but I thought I'd mention it anyways.

What other fish etc do you have with it? It kind of looks like it might be getting picked at.

What sort of lighting and flow do you have for it?

[zum14]

OK so I have 2-36" T5HO dual lights with one power glo and one marine glo (i realize that theres better out there now and will be getting something better for the next tank) The acan sitting about 3 inches off the ground, Tank is 20" tall. I would say its in a medium flow area. All I have in my tank is a cardinal fish, two peppermint shrimps, one blue knuckle hermit, and 4 blue legged hermits. There are the usual bristle worms every now and again noticed on the rocks, few flatworms, um oh well i have noticed a small crab that hitchhiked, its impossible to get a pic as i dont see him often but what i can describe is its small, i think black and has these fan like antennea off its head. It seems like its staying retracted and not getting food or something, im not sure what necrotic tissue looks like but will google. Thanks for the help!

[whatcaneyedo]

I've often heard reports of people having their coral eaten by crabs (and occasionally shrimp) so that is where I would lay the blame. I've had a few problems in the past so I no longer keep any crabs in my tank. If you cant remove the crabs or the acan try guarding the acan by building a cage of gutter guard, egg crate or some similar material and see if that works.

[zum14]

Will the guard not block too much light? If its a predator problem... you want to try and rescue it?just suggesting. (i also dont want to give it away if its sick or something) Im not sure that protecting it is a long term solution. If it works and it comes back, its just growing the food back to health again right? and im not sure anything i can build will have small enough holes to stop predators but not suffocate it. The one hard to id crab sneaks in and out of the liverock. Id rather not sacrafice anything. Im having a tough time deciding on what i would like to have in the future. I love corals but also my favorite fish is an emperor angel, funny thing is i also love clams. haha . I might end up with some basic corals that they tend to leave alone and then play around with some of the fancier stuff in the frag tank i have planned. Im not sure yet. Let me know, id love to try and fix it but dont have the resources yet for stable quarantine and im not sure im ready to start tearing my tank apart to get all my shrimp and crabs out. Thanks for the insite.