What is killing my reef?


New member
I really think I need some advanced knowledge here. This is the situation as briefly as I can summarize it.
110G RR Tank
180-ish lbs of liverock
1 in sand bed only in front half of tank
2x250W MH Ushio 10k
2x96W PC 03 Actinic
Sump with lierock also plumbed into a Tidepool II with more liverock
Magdrive 1200 GPH return pump
MTS Protein skimmer
29G seahorse tank fed from sump & drains into Tidepool II (2 seahorses that breed like crazy)
Couple of powerheads for added circ in the tank

The chemistry of the water is as close to dead on as you can get. Most recent tests yesterday showed:
pH 8.4
I stopped testing for Magnesium & Iodine when I stopped dosing them, but this problem has existed either way and has been ongoing for 3 months. That problem is that virtually no inverts can live in my tank. Current/recent past state:

Pulsing xenia-lasted 3 days
Common brown mushrooms-shriveled and struggling
Some new live rock I got w/ red and blue mushrooms-see above
Brain coral-hanging on for dear life
Some common polyps-nothing special-4 days
Sponge that came on live rock-was sturggling when I got it-lasted 1 day.
I had a spectacular crash of a 9 month old 125G about a year ago. It had done well up to that point, then for no apparent recent, just imploded. Never got it going again. Finally gave up and started completely fresh with the 110. All new rock, new sand, new almost everything. The only things held over were the protein skimmer and the actinics. The tank will seem to get a little better, then the dreaded red algae comes back, but this is certainly a sympton, not the cause. It seems that even some aiptasia on the live rock is dying as well. Snails will last a few days, then die.
Odd parts-fish do perfectly well. Nothing special-blenny, 5 green chromis, 2" purple tang, 2" sailfin tang, spotted hawkfish, couple of small gobies, 25 or so hermit crabs. Don't remember the last fish I lost, even when they were in the 125G.
The tank has only ever had RO/DI water from a LFS that a gazillion other people use. Have used mainly Instant Ocean salt, though I have also tried a couple of other kinds with no apparent change.
I have tried to be complete with this, but if ANYONE has ANY idea at all what the heck is going on, I am all ears. If there are any other questions/parameters, I will gladly fill in the blanks. I have a few more days to try to work this out, then it becomes a fish only tank.
Just a thought...check and then double check your temp.. i had a digital thermometer that was ten degrees off....i lost a lot of coral and it was the last thing i thought to check. All my other params were fine,,, HTH
I would have been more worried about the temp as well had this been happening more in the summer. However, just coming out of winter, I have been more concerned with keeping it warm than cool. The problem seems to be about the same regardless of the time of year.
Thanks for the reply.
Similar Problem

Similar Problem

Im having somewhat of a similar problen myself, and am at a loss also. Funny thing, I have a large Hammer coral which I think would be most sensitive that looks fine, but my xenia, green star polyps, and a hugh 7 year old green nephtia(sp?) colony are barely opening for the last month. Ive done H2O changes out the butt, vaccumed my gravel, searched for lost items in tank that could be polluting the water, ran carbon, and have even ordered a new H&S skimmer which will be much more effective than what Ive been using for the last 6 years. Hope you get some ideas from what Ive tried so far.

Check & double check that you do not have any copper or brass fittings anywhere in the system.

Sometimes hard to determine the cause. You need to re-check all your thinking. I would start with a good lab grade mercury thermometer. You can purchase online for 25.00. Also you didn't mention your salinity, get a good refactormeter. check and double check all your levels. I have used 3 different calicum test kits and had 3 different readings. As much as 100 points difference. Lastly I would purchase a RO/DI and get a TDS meter. To double check that. Make any changes slowly... Good thinks take time, bad things happen in a hurry....
Stugray brings up an interesting point. I do have two brass check valves plumbed into the system. One is on the pump that returns into the main tank, the other is on the pump that goes into the adjacent seahorse tank. I actually thought brass fittings were OK and would not break down over time. Anyone else have any opinion on using brass? Again, just want to reiterate that only inverts in the tank have ever been affected, not fish. Also, if not brass check valves, what other options are available to prevent backflow? Or, if not brass ones, what other types are around? I had searched around for stainless steel ones, but was not able to locate any. Maybe I just did not search hard enough.
Baldgeek, Do these brass valves come in contact with saltwater from your tank??? The only safe metal to use is titanium.. Stainless steel isn't safe either. This could be your problem, I would replace ASAP... Also on the check valve, is this used to keep backflow from overflowing your sump???? If not go to large reef tanks in forum under plumbing my new system. There are pictures of a swiss wye check valve in plastic...

Good Luck.
The check valves sit above the water line in the sump (both pumps are in the sump, just pumping to different places), but of course contact the water as it flows through. I did make a special point to put them above the water line, but I would love to take them out given an alternative. I had just not been able to get a definitive answer before as to using or not using brass in the plumbing.
I will have a look at the wye check. Thanks!
If saltwater contacts the brass. Than you have your answer to your corals dying.. Also you will have another answer if your power goes out and your sump can't handle the water backflow. Check valves are not made for reef tanks.......
OK, well fortunately, there is a Ryan Herco distributor here in town (Austin) and I am calling them right now to see if they have the Y-Check valves in stock. Luckily also in that if they don't have them in stock, they can get it from Houston overnight.
Now, after having changed these out, is a large water change in order? Is there some other method to get rid of what is already there?
Unfortunately, the local shop does not have them, but they are ordered and on their way now. Obviously, the brass ones are coming off right now. I guess I don't have to worry much about backflow since that would usually only happen during thunderstorms and it never rains here anymore anyway.
Fingers crossed.
Thanks ricks. I sure hope this does the trick.
You may still have problems because the copper that got into your water from the check valves may have been absorbed into your rock and sand. It will probably continue to leach out of those even after the offending brass is removed. You may end up needing to replace anything that could have absorbed copper. Some would go as far as saying that the tank should be replaced, too.
Would that show up on a copper test? I had previously tested for copper and it only barely tickled the meter, as it were. I am not much of a chemist at all, and I just looked up and found out that brass is essentially copper and zince, but is the copper in these valves just copper or is there reason to believe that even if it does not show up on the copper test, there might still be some hardmful form of it. Is there a zinc test available to the commoner?
I ask mainly because I have already done this once and because I likely just made the situation worse by putting more rock into the tank last week. There is a shop in town that supposedly tests for heavy metals, so I can run some over there and ask.
One of the ironies about this situation is that if the valves turn out to be the culprit, I would have completely overlooked the the source if not the cause. There were times when I was too busy to run down and get RO water or to prepare my own, so I just used dechlorinated tap. One of the theories early on was heavy metal poisoning, copper, coming from the pipes in the house, hence the aforementioned copper test. Same result, different cause.
I should have specified that the part about dechlorinated tap was a reference to the 125G tank where this problem started. The current tank, the 110G, has never had anything but RO/DI water in it.
I agree with doug.. You know the brass valve is the cause. You may have to replace all your rock and sand. Just because you can't test the coppper, doesn't mean it's not there you corals have told you that. As for the check valve I won't use one at all. Correct you sumps capacity to handle the backflow. If not you will be sorry down the road. When I first entered this hobby. The guy at the LFS sold me a y check valve. And told me to check it often. Well a storm was coming, that morning I shut off the power. It worked fine, that evening I come home. And the damn thing had failed 200 gals of saltwater over the floor. All my coral high and dry baking under halides.... Bottom line it's up to you....

Happy reefing....
Good advice all the way around. I think the valves were the culprit. I removed them yesterday and am doing without for right now. In all honesty, I probably dont have anything to worry about with backflow anyway as I think there is enough sump to handle it, I am just paranoid I guess.
Anyway, I removed the valves yesterday, then as a short term "fix," I put in some Prime (about a half a bottle), then added some stress coat last night. The brain and another coral that was totally shriveled have already responded. I think another large water change is in order for the weekend. I would look into the filters that were suggested, but I can't see them getting here before the middle of next week, even with fast shipping, so I think I have to rely on the old "the answer to polution is dilution" for the time being.
I am hopeful about the state of things for the first time in a long time though.
I really can't tell you guys how much I appreciate the responses and ideas. It sucks in a way that the answer (seemingly) was sitting in front of my face the whole time and I just could not see it, but I think this finally coming to a resolution. Really wish I had done this earlier. Thanks for all the help. A special thanks to ricks who nailed this. I will post again after doing the next water change and let you guys know what the state of things is.
Dude... You can check your backflow into your sump. All you need to do is turn off your pumps while watching the water rise. If it stops draining before your sump overflows. You home free and can leave the house, and sleep like a baby....

I agree that the brass valves are a likely culprit, but what about salinity? I don't see any mention of it in your initial post. What is it and how do you check it?