mysterious toxic reef tank

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pancakes

Aquarium Advice Newbie
Joined
Feb 23, 2011
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3
i have a 4 year old 30 gallon reef tank that started to die off a month ago. the tank was truly perfect with not a single problem until i introduced a long nose hawk who didn't make the move very well. after a couple of days of being as boring as a hawkfish, he died and i removed him within a few hours his demise. about a week later my other fish started to drop out one by one. starting with the flame angel followed by a bi-colored blenny and a couple clownfish and finally the inverts; banded shrimp, cleaner shrimp and about a dozen hermits. these were all total veterans in this system and had survived long power outages and a couple of other stresses. in other words, pretty hardy little guys. what lived? a bunch of different mushrooms, most of the snails, a sand sifter star and boatload of zoanthids, though i thought they had died becuase they were closed and mucousy.(more about the zoo's to come...) throughout this process, i did several water changes(fresh from the ocean), changed carbon and vacuumed sand but stuff continued to die off. finally, once all of the fish were gone, i decided the zoanthids, which had basically overrun the tank might be the source of my problem so i removed all of the rock with them on it and scrubbed those little closed up nubbies off and gave the rock a nice fresh water rinse,(well water, not tap). other life on the rock did just fine(mushrooms, little feathers, etc.) i did take one piece with the zoanthids to a friend's system to see if they would open which they did. i feel a little guilty about killing all of those others for nothing but honestly, they were so aggressive, i'm sure they'll be back once i figure all of this out. okay, so THEN i did a 100% water change and started over with a few chromis. all of the fish died within 24 hours in my system. before it is assumed that these fish were stressed, i will note that the 100% water change came from the same system the chromis came from and fish were properly acclimated. at this point i assume that some piece of equipment is somehow polluting the tank so i replace the filter(whisper 60 replaced by penguin 350. yes i know a wet/dry would be better but trust me, this system was cranking), removed the powerhead and protein skimmer and proceed to cycle the tank with all new equipment. after a couple weeks and another water change things are starting to open up a little so i decide it's time form another chromis/canary. no luck. still a death tank for verts. the reamaining zointhids are about 1/3 open and the mushrooms look to be about 80%. something i didn't mention is that my levels throughout this whole ordeal have been GREAT. amonia, nitrates, nitrites, PH, Alk. all right in the zone. i use C-balance regularly and also add a little iodine. but there's clearly something nasty living in my system. is there a way to test for other disease? i'm very hesitant to throw out all of the rock becuase it's still thriving and beautiful. also, i don't think i can go on not knowing what the problem was. did that little hawkfish bring something with him that could be lingering? it's been recommended that i toss out all of my rock and sand and start from scratch but the mystery factor will keep me up at night. i HAVE to know! any way to test water more thoroughly than the off the shelf kits? something i might treat with that won't kill the rock?
 
Do you test for iodine? Adding too much iodine can be toxic to the tank, I'd check those levels as my next step to figure out what's happening. Don't throw out your rock and sand just yet, just leave the tank fallow for a while (6-8 weeks) to let any bad diseases die off and give your self time to figure out what's going on.

Edit: I'd also read up on "Old tank syndrome" to see if some of the symptoms match yours.
 
i agree. i believe it was the addition of additives. you don't have anything in the tank that is using up the calcium, alk and iodine, except for maybe calcareous algae. . did notice that the crabs and/or shrimp seemed to molt often?
 
An other problem is over cleaning. Don't clean all your equip. at one time and don't vacume the sand in the DT as this could release Toxic materials in an old tank.
 
hmmmmm, not sure i agree with the overdose theory. i'm really meticulous about correct dosages and if anything i under-treat my water with these things, especially iodine. plus, wouldn't the many water changes have corrected this? at this point i'm dealing with brand new equipment and a 100% water change right from the ocean and the system is still killing chromis fish. i realize that i'm uncycled but chromis??? i can only assume that the rock and/or sand have some infection. i'm one step away from tossing the rock and bleaching the tank. this would be a disaster. can anybody recommend an antibiotic treatment before i go nuclear?

thanks!
 
Sounds to me like the tank was chemically contaminated with something, from the way you describe the original die off. I agree with you though - with the 100% water change you did, I'd figure whatever was in the water was gone. Unless... it's something in your water. You mention using "ocean water", but that definitely doesn't guarantee purity. In fact, it probably guarantees that you're going to have stuff in the water that you have no clue about. The ocean - unless you're way off shore - is anything but clean.

How about heaters? Have you checked to make sure those are still sealed tight and not leaching anything in the tank... like electricity?

Like Krypt mentioned, it's easy to overdose Iodine, even if you're testing for it. (And you *are* testing for it, right?) Ca/alk... sure, that's OK to dose - but I'd leave the iodine alone. Too easy to screw up and wipe out a tank.
 
you know, i haven't checked the iodine levels. is there a kit you can recommend? it's still not at the top of my list though because i only added a few drops if i went too long without a water change. but i will check it, thank you. i hear you on the ocean water too. i know it can't be totally clean but my source is very good and only collects water on a strong incoming tide. i know that's not foolproof but i've never had any problems before. plus i've done so many water changes over the past month, seems unlikely that i keep getting bad water. what about an antibiotic, anybody ever had to do that?
 
An antibiotic is only going to kill bacteria. Not much good if it isn't a bacterial issue.

I've never used any iodine kits, since I've never dosed it. But if available in your area, my first choice would be a Salifert kit. The rest of their kits are very good.
 
Mantis shrimp? Very unlikely since the zoas closed up and it sounds like the fish died slowly....just thought I'd throw that out there just in case haha
 
The stage your at right now, just treat the tank as if it were not cycled. With all the cleaning and the 100% water change you have done, it's possible that you removed alot of the nitrifying bacteria, so when you added the chromis the system spiked, killed them, and left you with a mystery.

If the original problem was an accumulation of iodine or some other chemical, chances are you removed it. At this point I would recommend leaving it fish/invert free for 6-8 weeks, run some GAC to clean the water further, and start using some RO/DI water and artificial salt mix. I know you've stated that there hasn't ever been an issue with using ocean water, but since you still don't know what exactly wiped your tank, it would be a good idea to cut out some of the variables and ocean water can contain ALOT more then pollutants.
 
not testing for iodine and dosing it is not being "meticulous about correct dosages". you have no idea how much is being used. you are adding plenty with your water changes already.
i would also look to the ocean water. the live rock that is aquacultured is done so miles off shore. i'm sure it would be easier to aquaculture this rock 30 feet from the beach, but they don't pick spots that close for the reasons above. the shore lines work very much like a protein skimmer in that the ocean expels it's waste there. i don't think it's unlikely that you would get bad water from there on multiple occasions.
 
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