Monti Issues

So, I am reaching out for additional help.

I have a fairly new tank. 3ish months old. I have several types of coral: Mushrooms, GSP, zoas, palys, acros, duncan, poccis, a leather, and several types of montis.

All my coral (save the duncan, I always have issues with them) seem perfectly happy. Pocci have great polyp extension and acros have gotten some amazing color since added.

Except my montis. My monti caps seem happy... but others have struggled.

At the same time I added my monti caps, I added a montipora spongode and a montipora setosa. Both looked extremely happy. Then, the spongode showed a spot of RTN. The rest of the coral seemed fine (with polyp extension) when I left. I came home, and it was 3/4 gone. Still with polyp extension. Did an iodine dip, but by morning it was gone.

Flash forward like 2 and a half weeks, and now the same thing is happening to my setosa. I immediately did a dip. When it continued to spread, so I fragged off a part of the good section, and dipped again. However, the good section now is showing RTN, and looks like a goner.

I'm at a loss for what is causing this!

Salinity - 1.0245
PH - Stable (probe not calibrated so number isn't accurate, but it's only ever +- .15 or less)
Amm - 0
Nitrate - 0
Nitrite - 0
Temp - 77.5
Alk - Between 8 and 9 (slight green tint at 8, super green at 9)
Calc - 460 (not dosing anything)

Lighting - LED

 

sound more like you have mont eatting nudibranch, then your perm. i would do a check for nudibranch and black bugs.

what are you dosing for the alk?
how offen and how much at a time?
what is your Mag ?

 

What is your mag at? I've had issues with some of my coral when my mag drops too low.

 

So far, I haven't seen any but that doesn't mean there not there.

Dripping Kalk for my Alk

Feeding Daily. Couple pinches that are generally eaten quickly (more concerned that my shyer fish aren't getting enough food then that I'm overfeeding).

Currently don't have a test for Mag

 

What is your mag at? I've had issues with some of my coral when my mag drops too low- my duncan was a prime example, which may be why you've had such difficulty with them?

 

Potentially. I'll need to order a test.

 

I would. If you are keeping corals, Mag is important to track. In the meantime, you may want to do a water change, as that will help replenish some elements.
How often / how much do you typically change the water?

 

Biweekly. usually 20 to 30 gallons.

 

forgot to ask- what size tank?

 

90 gallon display, 20 gallon sump, 30 gallon fuge.