Shelly's 65 Gallon

[989ShellyJ]

Thought I'd say hello and post a few pictures of my setup.
The tank is my first, although I've had freshwater for many years. It was started in April 2014.
Sorry for the super blue hue, I'll grab another picture soon with the cool whites on.

[MizTanks]

Hi Shelly!! Our tanks are about the same age So what's happening with yours? Good news/bad news we want it all-lol. What lights are you using? Sump/no sump? Oh and yes more pics are a must!

[989ShellyJ]

I meant to add more pictures but get an error every time I try and upload.

The tank is doing really, really well. I think it is nearly complete in terms of corals. I'm looking to add a few more specimens, namely an anemone, monti(s), and some pocillopora.

Most of the existing corals came from another tank I bought from another person back in August. They were getting out of the hobby and had a 5 year old 30 gallon Innovative Marine Aquarium complete setup - corals, fish and everything. As a result, I know what most of my corals are but not all . I'm now using the 30 gallon as a quarantine tank, having transferred everyone to the 65 gal.

I have a 20 gallon sump with a NAC7 Bubble Magnus clone skimmer from SC Aquariums. The light fixture is a DIY one I built using CREE LEDS and the whole system runs with an Apex Neptune PLC.

I currently have only 6 fish: a yellow tang, a banggai cardinal, a purple dottyback, 2 clowns and one lyretail anthia. I plan to add more small fish because I like the "schooling" look.

I'm also running two reactors with GFO and Carbon.

[989ShellyJ]

Update with a question:

Certain corals are doing great in my tank and others... not so much. Some were doing well but now seem to be ailing.
Corals that are doing well are the various mushrooms, the ricordeas and the blasto. My aussie torch is happy and some of the zoas are growing and spreading fast. My forest fire digi, Hawkins Blue Echinata, Garf Bonsai, ORA Pearlberry -- all super happy.

However recently (in the last 2 weeks) my previously super happy green birdsnest, some of my orange setosa frags, sections of the pink pocillopora, and some of the ?unknown? acorpora have started to lose polyps and die back from the tips down. The tissue recedes and all that is left is a brownish "fleshy" film. I'm concerned because it seems to be spreading. Basically my corals starting showing this issue around mid-March.
I haven't changed lights or flow. On March 7, did change out all my carbon and GFO in the media reactors because it had been about 4 months since I had changed them. I also run some Purigen (new) in the sump along with Chemipure elite (always had this) and I changed these two at the same time as the reactors. I didn't test for PO4 or NO3 before hand.

I have tested several times since and PO4 = 0.00-0.02 ppm; N03 = 0-0.5 ppm

I typically do a 20% water change (12 gallons) every two weeks. I used Red Sea salt (black bucket) but in that same time frame I did run out and got the Red Sea Pro (blue bucket)

I test for Ca, ALK and Mg and "try" to dose manually to keep them constant. My desired levels are CA=425, ALK = 8.0 dkh and Mg =1400. However, my alkalinity seems to naturally stay much lower - 5.3-5.6 dkh while the CA and Mg don't vary much. I carefully dosed ALK starting 3/12, gradually creeping to the 8.0 dkh mark over 4 days. I only raised it .8-1.0 dkh per day until I got to 8 dkh on 3/16. Then, I measured and found the ALK dropped about .4-.7 dkh for each 24 hours and I dosed to overcome that every day until 3/21. During these 9 days, I only had to dose CA twice to stay at 425 ppm. I measured all three levels every day.

On 3/21, I wrote in my log about noticing the blackened tips on the green birdsnest. I think it started slightly before that but that's the first time I wrote it down. I tested all parameters and found the water quality to be fine.

I continued keeping the ALK at 8.0 dkh for two more days (3/23) and then let it drift down to 7.0.

I have read the following possible explanations:
that this is RTN caused by changing all the media at once and dropping nutrients super fast
that this is Alkalinity burn
that this is a disease
that there is too little light (unlikely since that hasn't changed in the last month)
that there is too much light (same as above)

Sorry this is so long but I'm not sure what to try next. Thanks for any insight.

[MizTanks]

Sometimes reactions to certain things can be just as slow as they are fast. It took 6wks for my 5yr old Favia to start bleaching from to much light. Moved it and 2wks later she was back to normal.
I also know that ALK swings are very hard on Acros. Weakening them, thus making them susceptible to disease. Couple that with media change and I would expect some loss.

Personally I wouldn't try anything else. Let things settle down. Maintain parameters, keep them stable at whatever numbers you choose.

[lifeoffaith]

What lights are you running and what size is the tank? Sounds like your low light corals are thriving and those that need a little more light are suffering which is why I ask.