HELP!!!

[Somethings Fishy]

Awhile back I had a severe infestation of something in a tank that killed all my fish. I suspected a gill parasite & an intesinal parasite but never found anything that helped with the problem.

The tank ended up being totally stripped, everything bleach sterilized & all the substrate & decor were replaced. The tank now has a colony of Geophagus Steindachneri, 2 Pictus, 1 Goldspot Plec & 5 Bronze Corys. The corys are not my idea, blame the missus for sneaking them in when I wasn't paying attention.

I now seem to have the same problems all over again. The fish are flashing/scratching frequently. They all have a greatly increased gill rate. Some are hiding out when then normally wouldn't. Most of them don't want to eat. This morning I found a dead Cory & I have just fished a dead female Geophagus out. Last night I began treatment with Malachite Green with Formaldehyde on advice from LFS.

Now the same thing has happened as last time just before all the fish died. The water has turned a very cloudy white like a bacterial break out.

I have removed what I can to a bare hospital tank but I still have the plec & 3 Geophagus in the tank that I simply can't fit in anywhere else.

I've tried the usual blues & greens in the past with no success & I have also tried Sterazin & Tri-sulphates with no success. My water parameters are ammonia 0, nitrite 0, nitrate 2, GH 9, KH 7, PH 6.8, Temp 24.5C. The tank has been running for about three weeks with a fully cycled filter from a problem free tank & the parameters have been stable for the last two weeks. I carry out a 25-30% water change every week & for the last 4 days I have been doing 20% per day due to the problems I am having. If anything the water changes seem to make things worse on the fish. I have tested my tap water for heavy metals & other contaminants but there is nothing I can detect.

Does anyone have any suggestions?
Last time the water turned white I lost all my fish within 24hrs. Seeing as the water tuned white early this morning I am expecting all the fish to be dead in the morning.
I've been fighting this problem for well over a year including the last lot of fish to go through the tank. I'm so close to giving the hobby away altogether that it is ridiculous.
What can I do? I'm desperate.

 

[jsoong]

It does sound like a parasite of some kind, might even be ich in the gills. Stick with the Malachite green & Formalin for at least a week since that is how long it takes for the meds to work.

Meanwhile, I would suggest continuing with the water changes. Even though your water parameters are good, fresh water should not hurt. However, with big water changes, you need to make sure that your change water matches the tank water parameters (temp as well as composition) to prevent stressing out the fish. You might want to test your tap water just to be sure. And don't forget to use a dechlorinator in the change water.

BTW, what test kit are you using? A KH of 7 (degrees?) usually is not associated with a pH of 6.8.

 

[Somethings Fishy]

I use API liquid tests for GH, KH, Ammonia, NO2 & NO3. I think its caled a Vita-care test for co2ppm.
My tap water comes out with those properties & diy co2 with no added bicarb lowers the PH.
Those KH/PH charts that give approximate co2 levels are a load of BS & not even close to half accurate.

It's all irrelevant now anyway. I've managed to sort the problem out & the tank & equipment/decor has all been sterilized cleaner than any operating room. I even boiled the 125kgs of gravel substrate. Just started adding food to get the tank started on it's cycle this morning & the fish can start going back in there in another week or so when the medication has run a second course just to be sure I got rid of the problem for good. Unfortunately pure ammonia is not available in Australia to the public so I have no choice but to do the cycling with fish. Heaps of water changes & monitoring will make sure they are in no danger though.

I age my water for a week in a seperate tank (also sterilized) after I have set all the parameters. GH, KH, PH & temp. My co2 is rigged to this tank as well so that the water composition is absolutley identical before I pump it into the display tank.

Thanks for your input though.

 

[jsoong]

I use API liquid tests for GH, KH, Ammonia, NO2 & NO3. I think its caled a Vita-care test for co2ppm.
My tap water comes out with those properties & diy co2 with no added bicarb lowers the PH.
Those KH/PH charts that give approximate co2 levels are a load of BS & not even close to half accurate.
.....

Sorry, didn't mean to imply that you did not know how to take care of the water. <I didn't know you are injecting CO2, so I thought the numbers were strange.> It seems like you have everything under control.

Those KH/pH/CO2 charts made some assumptions. The main one is that there is no other buffers in the water other than bicarbonates. Any other buffers will throw the numbers off.