I need help figuring out what happened

[evan127]

So, I originally posted a similar thread on a different forum.  I am in need of some help.  I'm not sure what is going on with a few specific acroporas in my tank.  Seemingly without changing anything about my reef, poly extension has been slowly degrading on a handful of acros. I'm not sure what has caused it. I've checked for pests, even at night with a flashlight. No bite marks or any sign of irritation of the tissue. The zooxanthellae is dense in all of the affected corals.

 

Before we go any further, here is the obvious stuff:

Display - 120 gallon

Lighting - T5s (4 Blue+, 1 Coral+, 1 Purple+; 2 Blue+ are on for 10 hours - 2 Blue+, 1 Purple+, 1 Coral+ are on for 5 hours) Bulb order front to back is 2 Blue+, 1 Coral+, 1 Purple+, 2 Blue+

Flow - Two MP40s on anti-sync Reef Crest at 100% (24/7), return is a Vectra M1 on 75%

Skimmer - Vertex Omega 150 (24/7)

Refugium - Live rock, MarinePure block with chaeto lit opposite display lights

Mechanical - 2 filter socks changed every 3-5 days

Fish - 6 small fish

 

Parameters from Tuesday (5/23)
- Alkalinity - 8.4dKH
- Calcium - 450ppm
- PO4 - 0.00ppm
- NO3 - less than 3ppm
- Water temperature - 77.6F
- Salinity - 1.026SG/35ppt

Here is my original thread with others' replies and more information that I might have over looked here in this post: https://www.reef2reef.com/threads/sudden-rise-in-calcium-inhibit-polyp-extension.304677/#post-3776996 Please help. Even if its something super obvious or something you don't feel is worth posting, please post it. I really need advice as I am running out of ideas myself.

Thanks,

Evan

[lkoechle]

could be too little nitrates.  I have an acro right now with zero polyp extension and I think the water is too clean.  My fish are in QT and I left the skimmer running by mistake.  So, I think thats the problem if everything else is good.  

[Clown79]

With low nutrients in the tank, are you feeding your corals?

 

Do you dose any alk/ca to maintain those numbers on a daily basis?

 

 

[evan127]

17 minutes ago, Clown79 said:

With low nutrients in the tank, are you feeding your corals?

 

Do you dose any alk/ca to maintain those numbers on a daily basis?

 

 

I guess I left out that important information!  Yes, I dose BRS two part on BRS dosers. Both calcium and alkalinity are dosed once per hour with a half hour offset from each other.

 

I was was feeding my corals 1/8tsp Reef Chili, 10 drops Pohl's Coral Vitalizer and KZ Amino Acids nightly, but its now down to a few nights per week.