Crook Fish

[Somethings Fishy]

Very sick fish

My 6x2x2ft has 2x oscar, 1 x green terror, 1 x nicaragua, 1 x featherfin & 1 x bristlenose. The tank has been established for about 3 years with no changes in the stock at all.
My water parameters are GH 9, KH 6, PH 7.8, ammonia 0, nitrite 0, nitrate just registers. I test my water just before a water change & again 4 days later. The parameters are stable. I know the PH is a bit too high but the fish were all born & raised in the exact same water conditions. I do 150lt water change every saturday. I age my water before use in a bare tank with a filter seeded from the main tank. I set all my GH, KH, PH & heat before adding to the main aquarium.

Over the last 2 months the fish in this tank have developed a series of symptoms that has me very worried & completely baffled.
It started with scratching/flashing that has gotten worse with time. Now bad enough to remove scales. Next the terror & nicaragua started head shaking & shimmying. That has also gotten worse but only those two fish do it. Two weeks ago things started to get rather disturbing when the fish stoped swimming around in favour of holding position near filter outlets & airstones in a 45 degree headstanding position. They appear to be gasping for air but are not going to the surface unless it's to eat. The terror sits on the bottom but none of the others do. The fish have turned shy & all hide when I come near the tank. I could hand feed the terror & oscars 2months ago. Now 4 days ago everything except one oscar went off it's food & haven't shown any interest in eating since. Faeces are white & stringy, thick & thin.
I feed HBH Flake Frenzy, Oscar Grow & 8 Veggie Flake with a weekly feed of guppys I breed myself & a weekly feed of frozen brineshrimp or bloodworms. Twice a day what the fish can eat in under 3mins with the excess removed immediatley if there is any. Friday is a fasting day.
The symptoms started while I was treating a whitespot outbreak with trisulphates. After 2 weeks of the whitespot treatment I gave them a break for two weeks then ran a course of sterazin as I believed it to be a gill parasite but the treatment hasn't done anything.
Now that the fish have had a rest after the sterazin I'm looking for the next thing that this may be. I've been through as much literature as I can find & can't come up with anything that fits with all these symptoms so I'm thinking multiple problems. Maybe intesenal parasite, I'm specifically thinking Hexamitiasis.
Any suggestions of causes & cures would be much appreciated.

 

[kaiofcanada]

I hope your fish are feeling better...but you might consider first that if you were treating whitespot/oick...that it does most of its damage unseen by infecting their gills. This makes is both difficult for them the receive oxygen and makes them lethargic. You will notice fish whose gills are infested with ick either gasping for air at the top of the tank or laying lethargic at the bottom of the tank. The flashing and scratching are also tell-tale signs.

I treat ick for at least 10 days after seeing the last manifestation of any symptoms. This typically is around 3 weeks in total. I prefer no0t to use chemicals as most are just as toxic as the infection itself. I feel sometimes it is adding insult to injury. I prefer to treat ick my elevating the temperature gradually to 90F/32C for 10-14 days. And adding a dose of aquarium salt to the tank per the instructions. BY raising the temp you of course reduce the amount of gases which can stay disolved in water so it is best to increase the aeration by adding a airstone or decreasing your water level to allow more surface aggitation form the filter outlet, or both. I do both. During this treatment I change the water every 3-4 days around 50% to both keep the water as clean as possible and to also remove as many of the free swimming trophonts as possible.

Treat ick until you are absolutely certain it is gone. Ick has 4 stages of its life cycle and can therefore reappear a number of times before it is completely gone. If any fish are still flashing, gasping for air, or show any spots, keep the temp up and wait it out.

It sounds like your fish have a great diet and that you are a very careful fish keeper. Ick can just appear. It is really just bad luck sometimes. Since you knew you had whitespot, I recommend treating your tank fully until you can be certain that it is gone. I would not use any more chemicals in your tank now that you have already tried two. I would also disinfect your water changing hoses and fish nets to be sure you don't have any creepies hanging around that can go back in the water.

Keep us posted on how your fish are doing.