Help.....SPS coral is dying off. SG is low.

[newreefer_59]

Have SPS coral (brown montipora and hydnophora) that has badly deteriorated the past few weeks. my LPS coral looks good and the fish look great. I have had to move out of my home as of last July, and the tenants have cared for the tank and I have done the water changes up until last month. Now, the tenants have done them too. However, she was not adding enough reef crystals as the SG level was only 1.021. We did a change together and raised the SG slightly and will continue to raise to the 1.025 area. Calcium was 420, Ph was 8.7, but KH was 10. Would the SG level at 1.021 cause the demise of this coral?

[riceboy]

check your phosphates

[asylumdown]

I had an equipment malfunction while I was out of town shortly after my tank was set up that caused my SG to drop to 1.015 over the course of 5 days. Some (most actually) of my SPS corals were toast, but some survived, and are now thriving. So, 1.021 is probably a whole lot of stress, and some corals might not be able to handle it, but I bet there are plenty of corals out there that could come through salinity that low just fine. It really depends on the species, what it's naturally adapted to, and how healthy it was to start.

Bring the SG back up slowly, and try and sort out if there are any other problems that might be inhibiting them. Also remember that an SPS that has been stressed can take months to fully recover.