Crash Goes the 180 Tank

[Buzz1329]

Disaster in my 180. I could not get the alkalinity below 8.0 or the calc below 475. Ordinarily not a problem, but I was trying to run ULNS tank using the ZEO method. Not sure why the alk/calc levels were uncontrollable. I stopped dosing KW, 2-part, and switched to the lowest alk/calc salt mix I could find – Red Sea non-coral pro. Did not make a difference. But after 5 months, things still seemed to be fine – SPS/LPS frags were looking good but not a lot of growth. Coraline algae was sprouting on Marco dry rocks and on glass. Then, I noticed that some of the frags started to look a little off.

Fast forward, and I noticed that some of the frags were starting to lose chunks of “flesh”. I pulled 15# of live rock I had purchased from reefs to go and this seemed to help a bit – alk and calc dropped slightly. But by then it was too late. Desolation row – mostly SPS frags but also lost a few LPS frags. 3 weeks ago, I started gradual withdrawal from ZEO system – gradually dumped Zeostones and decreased doses of ZeoStart and Zeo Bak. I added increasing amounts of GFO to Zeo reactor as this was happening.

Throughout this all, nitrates/phosphates were not detectable with Salifert kits, API nitrate kit, and Red Sea phosphate kit. Potassium tested consistently at 400-410 with Salifert kit. Ammonia and Nitrites were zero with API (Ammonia and Nitrite) and SeaChem (ammonia) kits. pH ranged between 8.0 and 8.2. Magnesium was elevated at 1350 to 1500 ppm but I don’t see this as a problem. Fish, CUC, tuxedo urchin are all doing fine, BTW.

So far, I’ve lost about 3/4 of the SPS frags and maybe 1/10th the LPS frags. I tried fragging the deteriorating frags but so far it has not worked. Like the parent frags, they gradually lose “flesh” (usually starting from the middle portion of the coral) and go downhill from there.

Now I am seeing weird 1-3 mm cream colored critters on the front glass of my tank in the morning. Have not been able to get a useful photo with my stupid camera as yet, but they definitely do not match the description/photos of any coral pests (such as AEFW) I’ve seen. But who knows? At this stage, I would not be surprised to see a plague of locusts devouring the contents of my tank.

IMHO, this is NOT a problem caused by the ZEO system. No ZEO additive would cause alk/calc levels to increase. The problem was my inability to conform the alk/calc levels needed for an ULNS like ZEO. I now need to dose 10 ml of BRS alk/calc solution daily to maintain levels at 8.0/450, so maybe it was the reefs to go live rock, but again what do I know?

I'm trying to ride this out and hope that my normal husbandry (10% water change per week, very efficient SRO 3000INT skimmer, GFO/GAC rinsed weekly and changed every other week, daily tests of alkalinity and calcium), will get me through. Any insights would be appreciated. (Other than, dude, your magnesium levels are too high – that’s the problem.)

Thanks,