Teracotta poison?

[birket]

Hi
I have been having a major problem with my Clown Loaches and Plec. 4 loaches have died, the Plec, and now my last Clown looks like its not going to make it.
I have been racking my brains trying to work out what has changed. Water tests for Ammonia, Ph and Nitrate/nitrate prove not to be the issue - they are normal. The fish that have died show now external symptoms.
The only thing I can think of is that about 2 months ago, I broke a small teracotta plant pot and thought that it would make a nice 'home' for the Plec to live under. It certainly did, and resided there most of the time. My clown loaches used the other half as a home. The tiger barbs and neon tetras in the tank did not use it at all.
I am wondering if over the two months or so that they have been living under the pot some kind of chemical has leached out of the clay and poisoned the fish. Like I said, there are no external signs, but before they have died, they have spend the time just lying and 'panting' at the bottom of the tank.
Any ideas?

 

[Cichlid Woman]

Was it painted or ceramic-fired terra cotta, or just plain clay?

-- Pat

 

[birket]

I think it was just plain fired - no paint, and it wasn't shiny which would suggest a glaze.

 

[wetmanNY]

If it had been used, it could have absorbed some insecticides or fertilizer salts...

but I think you might treat for external parasites, Costia and Trichodina etc., and at the same time eliminate any gill flukes. Look over the medications for ectoparasites at your LFS.

 

[RTR]

Plain terracotta pots should not be a problem in a tank, they've been used for such for years. But they should be new pots, not used. Used pots could have residual incesticides or such that could be a problem.

 

[wetmanNY]

Cancel my post! I prefer RTR's incesticides.

Great minds think... well, in parallel relays...

 

[birket]

I take your points, but the pot was only small - about 5 inches tall. Its only really had soil in it before (with a plant - obvioisly!), and I highly douby that we had used insecticide or anything like that. If we had used insecticide, surely the amount that could have leeched out into a 120 litre tank would be sufficient to kill 5 loaches and a Plec? But maybe it would? I don't know.
One of you mentioned parasites - I can't see anything though. Wouldn't you be able to see something? I even examined the bodies of a couple of the dead ones and didn't see anything.

The only thing I have noticed in my last remaining clown loach (which may by now be dead) is some red colouration near its tail - like blood inside that I haven't notoced before. Could it be internal bleeding or something? And if so, what would cause this?

Fish are a nightmare!

 

[TJcanada]

I doubt it was the clay pot - are you certian that no insecticides were used on the plant that lived in it?
Costia and Trich have been mentioned as possiblities - and Flukes - you will not see these with your "naked eye" you'll need a microscope. All three of these nasties love the gills and that's usualy where they are most numerous. You said you examined a dead fish - what did the gills look like? How long after it was dead did you do the exam?
Costia will sometimes will show as a very thin whitish/grey mucus coating over the body - very hard to notice and at that point has spread very far, likely hood of treatment being successful is minimal. It also kills very fast given the oppertunity to multiply(proper conditions which goes to water quality and stress of fish infected) - as can Trich.
With Costia and Trich salt treatments usually work - with Flukes you'll need something such as and MG(malachite green)/Formalin combo. Indentifying what you have in order to treat accordingly. Costia and Trich can be seen at 100xmagnification on a "cheap" microscope - Flukes can be seen at 40x. If you can get a hold of a scope by all means do so - in some ways it can be your best friend as far as your fish go. If not then someone else should be able to recommend a course of treatment to follow.
Hope that helps a little........

some red colouration near its tail - like blood inside

- possibly the beginnings of an ulcer - could indicate bacterial activity.

 

[birket]

Geez! How complicated is this? I stupidly assumed that you would be able to see parasites! Why would this affect only my plec and loaches? My tiger barbs and tetras seem fine. I did really enjoy my loaches, but I daren't replace them in case they get the same thing.

"possibly the beginnings of an ulcer - could indicate bacterial activity."

How should I deal with this?

 

[Darkangel]

No one has asked what size tank this is or how often you do water changes. Visible blood on the tail fin, which looks like thin streaks could be indicitive of ammonia poisoning. You say you did water tests and they prove not to be the issue. Are you sure the test kits work? Are they old test kits? What is the filtering like? It is strange that all the fish you are having trouble with are bottom dwellers. Also the clown loaches are the most delicate in that tank IMO. How big were the loaches? Small ones tend to be a little weak. Did you have all the loaches in the tank at once or have they been dying and being replaced? Just some ideas.