The QT Tank of Death!!!

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Menagerie

Aquarium Advice Addict
Joined
Jan 17, 2004
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Vancouver, WA
Okay, I have had it!!! We just lost our fourth cichlid in five weeks in the QT tank and she was not even sick!!! I’ll start from the beginning; keep in mind EVERY TIME we test the water the readings are normal—temp 78, undetectable levels of ammonia and pH 7.2. The QT tank is five gal with a HOB filter, which is in storage when not in use. When the QT tank is needed, water from the 80 gal is used. This little tank had been great while we lived in Idaho; we even raised a brood of cichlid fry.

First fish— L. caeruleus (Lemon Yellow cichlid) that was mouth brooding. She died after being in the tank for 24 hours with her mouth open. I researched lockjaw in cichlids and found it did occur. It was sad; all her fry had been spit out and were dead on the bottom of the tank. The fry were NOT ready to be on their own. The only new thing in the tank was a clay pot we had put in for cover.

Second fish—8-month-old cichlid baby. This little guy had been living in the community tank, but had gotten ick. He was being treated with Super Ick Cure (Aquarium Pharmaceuticals, Inc.) in the QT tank with the clay pot for shelter. He died after being in the tank over night. The ick was not that bad.
Third fish— H. bimaculatus (Jewel cichlid) that was the smallest fish in the 80 gal. She had been looking stressed and had some torn fins, so we wanted her to recover in peace. I do not believe she lasted the night in the QT tank. My fiancé and I blamed the clay pot. We figured everyone must know something we don’t know about clay pots. The clay pot was removed.

Problem solved right? WRONG!

Fourth fish--A couple of weeks ago we bought a beautiful 3.5" docile calico cichlid with a subterminal mouth. She was an impulse buy, but we knew we had/could find space for her. She was too docile for the 80 gal, so we put her in the 29 gal, knowing we are upgrading to a 50 soon. On Friday (Feb 13) I got tired of watching the cories cowering in the corner of the tank. She had done no harm to the other fish, but we decided to remove her and placed her in the QT tank with rocks from the 80 gal. On Sunday morning, she was dead under the rocks.

Does anyone have any idea what was wrong with the QT tank? My fiancé was wondering about the activated charcoal in the filter—perhaps some toxin(s) from the clay pot was absorbed by the carbon, and then leached back out when the tank was setup again, thus killing the calico cichlid. The old filter was a small Whisper HOB from Tetra, and we had been using the same bio-bag insert (w/ carbon) throughout all of these mishaps (allowing it to dry in between setups). How do you store your QT tanks when not in use? I know some of you keep your QT tanks running with a fish all the time, but we don’t have that much room. By the way, are clay pots safe to use in aquariums?

We have since changed the entire filter (Topfin HOB w/ new bio-bag w/ carbon) and placed in a very HEALTHY tetra to cycle the QT tank last night and he is doing well. Our P. socolofi is looking gravid, and after spawning in (likely) a few weeks she will be removed from the 80 gal to raise her fry in peace.
 
That is really weird. I have no real advice, only sympathy :(

It seems 24 hours isn't long enough to create enough ammonia to get toxic, and you say the tests are fine anyway....

What I would probably do is 'store' the filter for the QT running as extra filtration in a bigger tank to keep it ready for use. not that that hits the core problem.

Weird. :?
 
Some clay pots are treated with a fertilizer to help plants grow in them. This is obviously bad for fish, so it is possible that the clay pot had something to do with it.

I was told that many Wal Mart clay pots had fertilizer on them. My father stuck one in his 55g and nothing died, so I am not sure the truth of that.

It is a good idea to never put anything in a tank unless they are 100% it is fish safe. Even the most simple object can cause a problem in the right (wrong) circumstances. There is no way to know for certain if that clay pot caused any problem or not, but it sucks having to worry about it.
 
Yes, very weird and very very frustrating. :evil: I'm sorry you lost some beautiful fish. :cry:

Because the deaths happened so suddenly to otherwise healthy fish, I am inclined to think that poisoning was the cause.

Was the pot glazed? Most pottery glazes not intended for use with potable water contain heavy metal toxins. But that kind of poisoning is usually chronic and takes more than a day to become fatal.

So, my next thought would be a neurotoxic pesticide. In a thread a while back, someone raised concerns that new empty fish tanks were being stored next to pesticides in some Walmarts. Maybe the pot you bought had been stored near something toxic in the store - clay is extremely porous and will absorb/adsorb nearly anything.

Come to think of it, the smell of fertilizer and insecticide is overwhelming in any garden center I have visited. I'll bet any new clay pot is simply full of absorbed poisons! 8O
So thank you for posting your unfortunate experience - you nmay have saved someone else the same heartache. And good thinking to have removed the clay pot.


Regarding the Q/H tank:
Activated carbon will adsorb hydrophobic compounds for about a month, after which, it will simply leach them back into the water. For this reason, I stopped using carbon in all my tanks - I only use it to remove meds for a few days and then I discard the carbon.

When my 10 gal Q/H tank is not in use, I drain it and dry it out. I even break down the filter - I'm afraid of transmitting something bad from the Q/H tank to the show tank via the filter. Because of this, my Q/H tank is rarely cycled. If I use it to QT a new purchase, I squirt some BioSpira on the biowheel, check the params daily, and do daily partial water changes for the duration of the QT. I figure that if I use it as an H-tank, the meds would kill off the biofilter anyway.

I think you will be OK now without the clay pot and with a new filter cartridge. Keep us posted.
 
I have terra cotta (orange-ish clay) pots in all my tanks and have not had trouble. They were bought new for the tanks and I know they were not treated though. HTH
 
qt tanks...

I was going to ask where you kept it when it was in storage. Do you mean a basement or attic, or an actual storage facility? If it was a storage facility I would worry about possible chemicals or pesticides in that environment. One thing that I've done with fish tanks and decorations is wash them with soap. A lot of people frown upon that but as long as every last spec of soap is rinsed off you wont have any trouble. I never have and I've done it quite a few times. I usually use a mild dish liquid like Ivory or something. I just scrub with REALLY hot soapy water and rinse and rinse and rinse... Clay pots are kind of cool to look at i guess... But it may indeed be the problem. You may want to find something else for them to hide in. If you don't like the plastic stuff at the stores you could always try and make a more natural looking cave out of driftwood or coconut shells... :wink: If you haven't seen the coconut shells yet there a post on them in the classifieds, there's also a few pics in my gallery... Fish will hide just about anywhere they can. It's too bad you can't leave the qt tank setup more often. Understandable though. This pet store I use to help out in had a plant tank they would use as a recovery tank for sick or injured fish. It didn't cure big health problems but a good planted tank does benefit fish health in my opinion... That's about all I could think of... Sorry to hear about your fish. There's never an easy time to lose one. When you first get one it's frustrating because you spend so much money on them... after you've had a fish for some time you really do get attached... Hope you don't lose anymore...
 
Things like clay pots can absorb chemicals deep into the pot and then slowly leech out over time.
 
The clay pot was bought at Michaels--I usually buy them when they are 3 for $1 and use them in my houseplants. They are sold to make crafts with, and not sold with the intent of using for plants, so I do not think it was coated with anything. As for storage of the QT tank when not in use, it is dried and placed in my fiancé’s closest where he keeps his clothes and shoes. No chemicals or pesticides in there!

Enki--where do you purchase your terra cotta pots?
 
"The clay pot was bought at Michaels--I usually buy them when they are 3 for $1 and use them in my houseplants. They are sold to make crafts with, and not sold with the intent of using for plants, so I do not think it was coated with anything."

Well the thing is you never know where any given pot started off or where it has been. Even though it ended up in a craft store does not mean it is safe for fish. When making things like clay pots, all a vendor would care about is creating them as cheaply as possible (especially when they are 3 for $1 :)). Maybe it was cheap one day to just ship a batch covered in fertilizer instead of making another set of normal ones. No one is going to be eating off clay pots of putting them in their mouth so companies are not too worried about them.

One LFS by me actually sells fish/reptile safe clay pots for a few dollars each. They look like normal pots, but they are labeled for use in aquariums and reptile habitats.

When in doubt, you can cover anything in aquarium sealant, let it dry, and then put it in the tank :p :p
 
My clay pots i got from a high end garden shop here in town, they are made in italy and shipped directly to the shop, one big order every 6 months or so. Same store I got my rio powerheads from, they sell them for fountains. My GF works there so everything I get thru her is 30% off :)

No pesticides in the shop though, so no chance of contamination there.

I would agree that there is most likely some sort of contamination that has caused the previous deaths, simply cause it was so quick. It is like a murder mystery...
 
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