Whats wrong with my coral ??

[windcoast reefs]

Originally Posted by FWC

Hydrometer should be spot on ,salinity is at .027 when I last checked a few days ago.

Also test kit might be expired. I'll take it to a LFS soon for a second opinion.

Also I've been using plain tap water since day one.

Okay well my only guess is that it's the tap water, the reason most people use ro is for consistency. The tap water can have fluctuations in the phosphates, nitrates and even metals. It may have not shown up in the past but there can be sudden changes in the water quality. That is my guess, that or I have heard of the copper pipes in houses causing issues, it kinda builds up copper in the system and then can lead to a crash.

I would try doing some small water changes with ro water and see how things turn out over the next few days. Maybe run some carbon and phosban as well it will just help pull anything out of the water.