Encrusting Montipora secrets??

[jsousa]

I have 3 Montis in my tank now, a Sunset, a Rainbow and a Superman. All 3 were doing great at one point; incredible growth, great color and enormous polyp extension. Now, only the Sunset is continuing to thrive. Superman and the Rainbow are turning into brown rocks. Does anyone know what these guys need to thrive?

My params are, for the most part, within range...
ph: 8.0 - 8.2
KH: 9
CA: 460
Mg: 1550
NO3: almost 0
PO4: .03

I run a Prodibio system - BIoDigest, BioOptim and add ZeoVit supplements - AA, Coral Vitalizer, Potassium Iodide and Pohl's Xtra. SPS are doing great. LPS seem fine also except for a 4 year old Trachyphyllia and a head of about 20 Duncans which were also doing exceptionally well at one point and now don't seem to open.

Am I not getting enough food in the tank? Do the montis prefer a dirty tank? I'm starting to think the Duncans do. They've been closed ever since I started a low nutrient system. Of course, I feed all my corals once a week with meaty foods such as mysis, rod's, and cyclopeeze.

One more change that I should make known. About 3 months ago, I switched from Tropic Marin Pro Reef to Brightwell NeoMarine mostly because it was cheaper, about 20 bucks.

Any ideas would be awesome at this point. I'm really at a loss here.

 

[AndyH5512]

Browning is usually a sign of too many nutrients. Your Mag seems a touch high. Have you replaced your lights lately?

 

[jsousa]

My lights are about 3 months old.

Nutrients will definitely lead to brownout but that doesn't explain the fact that all of my non-monti SPS have been coloring up tremendously over the past 4 weeks while these 2 montiporas declined.

Wish I had a Hanna Phosphate meter. That's one reading I never trust from a regular test kit no matter how good they are. I use only Elos test kits.

 

[Znut Reefer]

Encrusting montis like a lot of flow. They grow faster to me it seems.