Caring for bubble coral

[dusked6]

I've been slacking on water changes and it caught up with me. CA dropping that low isn't normal, I know. Been keeping crazy hours and it fell by the wayside. Appreciate the advice.

[dusked6]

UPDATE. Thought it was weird my CA was off. Old kit, so I took a sample to my LFS. They confirmed the low reading, suggested a couple of dosings 48 hours apart. Owner's a friend, and he's big on partials, so I did one dose, then a small partial. Went back to LFS, different salesperson ran the test. Now we're at 500. Bought a new kit, tested a few days later - 500. Guess it was never that low to begin with. Just thought I'd share.