Coral Tissue Recession. Pests? Help!

[dcal1985]

For context, my tank has been set up for about 4 months and was doing great with solid growth in soft, LPS, and SPS corals. Over the past couple of weeks, I've had a couple corals with receding tissue and some complete death. I lost a very hardy birdsnest and several others are looking rough. On inspection there seem to be some white sponges growing on the base/sides (first picture.) Here are the latest parameters and some photos. Any suggestions would be much appreciated. Thanks!

Salinity: 35ppt
Temp: 78
PH: 8.1 average
ALK: 8
Nitrate: 3
Phosphate: .03

 

[carmodpg]

At 4 months, the tank is still very young and prone to some swings. In general, LPS like a little dirtier tank. I shoot for .06-.08 phosphates for LPS with ammonia at .10.

further, if those corals have not encrusted on the rock, although annoying, I would pull and dip in some iodine (and pluck the sponge off which is harmless, but could be annoying the coral).

However, the key to any tank, especially one that is still young is stability. So that is the main goal. Don’t try to overdue it and change things suddenly.

Finally, also ensure you don’t have any fish or inverts nipping at the corals.

 

[dcal1985]

At 4 months, the tank is still very young and prone to some swings. In general, LPS like a little dirtier tank. I shoot for .06-.08 phosphates for LPS with ammonia at .10.

further, if those corals have not encrusted on the rock, although annoying, I would pull and dip in some iodine (and pluck the sponge off which is harmless, but could be annoying the coral).

However, the key to any tank, especially one that is still young is stability. So that is the main goal. Don’t try to overdue it and change things suddenly.

Finally, also ensure you don’t have any fish or inverts nipping at the corals.

I haven't seen any nipping from fish but I'll definitely keep an eye out for it.

There really haven't been any major swings that I've noticed other than some variation in nutrients, which have been minor. I do think it's possible that I haven't been allowing for enough phosphates. That shouldn't be an issue for the SPS though, right? Those have honestly been impact more than the LPS.

Thanks for your help!

 

[carmodpg]

For the SPS, phosphates at .03 are not going to cause any tissue recession. Only thing that would is if they are bouncing from 0 to .03 routinely. Also, with a mixed tank, slowly raising phosphates and keeping that stable at .06 is not going to adversely effect SPS. Some would say that it will make them grow faster....

 

[dcal1985]

I've noticed a couple of these weird antennae sticking out of some of the irritated corals. Any thoughts?