Coral polyp loss

[Treefer32]

One of my largest corals is losing it's polyps. but my acros are growing. Phosphates tested at .12, nitrates at 32 (higher than I expected - high range red sea pro test), ph 8.0 to 8.1, salinity 1.025, alk at 9.0dkh (hanna tester). Temp 77 - 79. 340 gallon display - 2 years old in October. I've been doing two 11 % water changes a week (about 35 gallons each) with instant ocean salt. RODI water shows 0 TDS.

I do have a fair amount of asterinas growing in, but many are attached to the glass and other few on rocks. I included another coral that has white tips of a similar type of coral, but, I think the tips might be new growth. (it's been awhile since it's grown, but it's much smaller than the big one. Similar polyp type, but different color. The polyps are just hanging off the coral skeleton. It's been growing two years and just a few days ago polyps started detaching from the skeleton and just blowing in the water flow... I've tried taking a few clippings to save a few, but even the clippings are dieing off. Would the increased nitrates cause this? They're high but I have no algae growth in the display other than on powerheads and the glass. The rocks are clear of GHA. Some cyano on rocks, but nothing on corals.

 

[BighohoReef]

How has your Alk and Mag looked week to week? Has it remained steady?

PO4 looks a little high you might want to consider a phosguard treatment yo help lower it. Though I don’t think that is the main culprit.

is it possible you could have a stray current? Any shocks when you put your hand in the tank?

 

[Treefer32]

I actually had a electrical issue 2 years ago. When I had stray current it caused my corals (including this one) to grow much faster. Killed off 20 fish. the corals all grew better and faster with a current. I did some research and this was tried in the ocean with electrified cages to replenish several reefs. It worked, although not healthy for fish.

PH has been a little bit all over as oxygen levels in the house must keep changing. PH ranged from7.99 up to 8.2. A year ago it was between 8.1 and 8.3.

I run an algae turf scrubber, I'm thinking the nitrate and Phosphates will come down. I've been over feeding some to feed the corals with reef frenzy and reefroids.

 

[Treefer32]

Another thought, I increased my lighting photoperiod for an additional 2 hours with more blue spectrum light from my AI Hydra 52s. Would this impact corals to the point they just give up?

Another question would be I got some fish off of Divers Den. The fish looked amazing and are still alive. I put a couple in using a cup to grab the fish instead of a net. They just wouldn't cooperate with me and didn't want to stress them. They gently went right into the cup. So, much easier. I may have added a few ounces of that water to my tank. I don't know if Divers den includes chemicals (copper etc). The salinity matched my tank's salinity at 1.026 (same refrac). I don't know if 12 ounces of their water mixed with 340 gallons of mine would have that much of an impact to kill 1 coral very slowly.

I also noticed a bleached spot (just small right now) on my bird's nest. At this point I don't know if others are having damage from the higher nitrates or from something else. Not sure how to respond in a slow methodical but intelligent manor? Would I be better off running some carbon? I run 500 ml of purigen (just replaced a month ago).

 

[Treefer32]

I just discovered that my water softener is completely empty of salt.... Which is what fed my RODI. I know many people operate tanks without water softeners. But I'm on City water, would something have gotten through the RODI that TDS meters don't check for and would be harmful to corals? Rust? Chloromine? I don't know, just grasping at straws, the one corals horrible and the smell coming from my skimmer. My skimmer has never smelled this bad. Almost sulfur or rotten egg smell, which I get that smell if the skimmate is thick and near black. This is thin, brown liquid, fairly wet skimmate. It reeks like something died in my sump. I quite honestly don't know if I've smelled skimmate this bad.

My fish are all doing amazingly well. Feeding well, swimming normal, not showing signs of stress. Normal Tang drama, but nothing too wild and crazy. Other corals looking o.k. despite a build up of cyano. Which I attribute to the higher nitrates and phosphates. I'm continuing my twice weekly water changes. But not sure that's good if the water from my RODI is corrupted from the lack of softened water?