Super Sick Zoanthid

This was our first piece of coral and was doing great for about 6 weeks, staying open for long stretches and spreading rapidly. About 2 weeks ago the polyps started closing and not reopening. Algae appears to be growing on it. We followed recommendations on the forums and quarantined the coral, gave it an iodine dip, cleaned most of the algae; but she's not coming back and some of the polyps are starting to fall off.


Before quarantine, she was in a 29 gal bio cube with the bioballs removed and replaced with a small refugium.



Water parameters were

• 78.4 degrees
• 1.026 Specific Gravity
• 8.3 PH
• 9 Alkalinity
• 440 Calcium
• 0.25 Ammonia (were 0)
• 0 Phosphate
• 0 Nitrate
• 0 Nitrite

Known Inhabitants were

• 1 Porcelain Crap
• 2 Emerald Crabs
• 1 Scarlet Skunk Cleaner Shrimp
• 1 Royal Gramma
• 1 Purple Firefish
• 3 Turbo Snails
• 3" Xenia (total)

We also have found some hitchhikers on the coral after about 5 weeks -- a small crab that disappeared before we could identify it and a sea squirt (which seams healthy). There are white tubes (which can be seen in the pictures) we thought they were worms however when we tried to remove realized they were hard tubes. All seem to be empty.
Lighting:

• 1 36W True Actinic Blue Compact Fluorescent Lamp;
• 1 36W 10,000K Daylight Straight Pin Compact Fluorescent Lamp;
• 2 .75 Watt Lunar Blue LED Bar
• 1 .75 Watt Soft White Bar

Flow:

• 2 powerheads totaling 500gph

Water changes

• 10% weekly
• 50% after moving the zoa to quarantine

Any advice you could give to resuscitate our gal would be greatly appreciated.