I'm at a total lost

DomC · Nov 12, 2014

For the pass few weeks my sps coral have been hit with STN. I have lost a few small frags. I have bumped up water changes to 20% but can't seem to find the source of the problem. The system has been up and running for close to 2 years. I have taken most colonies out and try dipping them but still cont. with STN. There's no visual signs of pests on surface or within the coral. Not all colonies are hit with STN. Thanks for any advise.
Dom

System:
75gal with 40gal sump
Running GFO, Carbon 0.8
Lighting ATI 6 bulbs T5. bulbs under 5 months old.
Sal. 1.025
TemP: 77
Ph: 8.01
Alk: 7.8dkh Hanna
Cal: 458ppm Hanna
Mag: 1360 Hanna
Po4: .05 hanna
N03: 0 API
No2: 0 API
Amm: 0 API
Copper: 0 API

jolt · Nov 12, 2014

Maybe RODI unit needs maintenance?

Defective_Weeble · Nov 12, 2014

Stray voltage?

DFW · Nov 12, 2014

What kind of sps coral is affected? How long have you had these affected sps coral? Is your alk tester calibrated accurate? Can you test with test kit? Have you had any alk swings, temperature swings? What does "Carbon 0.8" mean? Are your corals starving to death? Do you feed them? Is there lots of flow?

DomC · Nov 12, 2014

jolt said:
Maybe RODI unit needs maintenance?

Replaced filters and DI about a month ago. Tested Ro/Di water 000TDS last night.

DomC · Nov 12, 2014

Defective_Weeble said:
Stray voltage?

No sure how to test for a stray voltage.

DomC · Nov 12, 2014

DFW said:
What kind of sps coral is affected? How long have you had these affected sps coral? Is your alk tester calibrated accurate? Can you test with test kit? Have you had any alk swings, temperature swings? What does "Carbon 0.8" mean? Are your corals starving to death? Do you feed them? Is there lots of flow?

On carbon it's BRS Bulk Premium ROX 0.8 Aquarium Carbon. I have been dosing BRS Soda Ash about 35mil a day with a doser. So no big swings that I have noticed. STN start with a Pink Milli I had for 2 years., Then my pink lemonade, hairy green milli, ASD pink milli, Blue Tenuis and few other no names. I use coral frenzy once or twice a month. As far as flow goes I have 3 1050 Hydor. I have test Alk with Hanna and Salifert and both with 1.1 dkh.

jservedio · Nov 12, 2014

You mention your parameters but don't mention stability and how often you test. A big spike in temperature, alkalinity, or large rapid changes in nutrients can seriously impact your SPS - particularly acros.

Sometimes, a large spike that you think didn't hurt anything won't manifest itself for a couple of months.

Additionally, if it isn't your RODI machine (mine caused problems even though it read 0 TDS - I had to directly test for phosphorus which was almost 0.1ppm), stray voltage, spikes, equipment failure, or an inhabitant of the tank, it can also be bacterial or some sort of infection. There are literally dozens of possibilities which could have started it.

You need to give a lot more information to really begin to figure out your problem. It's basically a process of elimination. By far the most common problems would be fluctuations in temperature or alkalinity - if you can rule those out 100% over the last few months, then start moving on possibility by possibility.

Also, unless you are certain what is causing your SPS to STN is capable of being treated by a specific dip, (AEFW, Red Bugs, Bacterial Infection), you likely exacerbated the problem since dipping is incredibly stressful.

DomC · Nov 12, 2014

The only few thing I could think of might be a temp. I use DA elite controller. I threw in a probe into the DT and read a few degs higher than what is displayed on unit nothing crazy. The other my powder blue killed a fish that I couldn't recover, but never noticed any big spikes in parameters. The other change I did was added a BRS screen to top of tank to keep wrasse from jumping out a month ago.

I test from twice to once a week. Salinity, Alk, Cal., and mag. I perform 10% water changes once a week except for the last 3 weeks. I have a separate TDS meter that I test to compare to ro/DI unit.

Ph swings from 7.8 to 8.1 from night to day. Alk will swing about 1dkh during the day. I have the doser setup to run for 5mins at 1.1mil every 4 hours.

cdness · Nov 12, 2014

Check for Stray Voltage...

All your other parameters look good. You are in the same position I was not too long ago when I lost about half my SPS over the course of a couple months. Nothing I tried worked, until I found the stray voltage. It is much better now, polyps are coming out again, and the corals are growing. So get out the multi-meter and check for stray voltage ASAP.

DomC · Nov 12, 2014

Thanks I test for stray voltage tonight. Had to look it up and doesn't look to hard to preform. I'll let you know the findings. The only crazy part it all my sps have good pe.