Fish sometimes get startled at night and panic and swim into objects or even the side of the tank and can damage themselves that way. Adding a bucket of water is unlikely to wash the catfish into a rock unless you dump the entire bucket of water into the tank instantly. If you do that the gravel would be blown all over the tank and the current could wash the fish into a rock, or you could wash the fish into the substrate and damage it that way. But if you slowly pour the bucket of water into one side of the tank, the fish will be fine.
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The white patches on the body could be related to the damaged eye and short dark barbels but it is probably coincidence. The fish could be weak and this would make it more prone to developing infections, whereas the other fish in the tank aren't getting sick because they are physically stronger.
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Any medications can harm fish so you need to follow the directions on the packaging. Fortunately most fish medications have 2 or 3 main ingredients (Formaldehyde, Malachite green, Methylene Blue) and they are relatively safe for fish as long as you follow the directions on the packaging.
The Malachite Green is for protozoans, Methylene Blue for fungus, formaldehyde pickles everything.
If you get a broad spectrum fish medication containing the above ingredients, it will treat the catfish for bacteria, fungus and protozoans. The Malachite Green shouldn't be necessary but if that is in the broad spectrum medication then it is fine.
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Sulpha/ Sulfa based medications can also be used and are safer for all fish. Triple Sulpha/ Tri Sulfa are normally available at most pet shops. Sulpha based medications will treat most diseases and can be used at full strength on catfish.
Sulpha based medications normally get treated every few days and if you monitor the water quality for ammonia or nitrite, you might be able to do a water change every couple of days rather than each day. However, if you get an ammonia reading, then do a full water change and retreat.
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You can either treat the fish in the main tank or move it into a quarantine/ hospital tank. Due to the rocks and curved front you might be better off using a 40 litre plastic storage container for a quarantine/ hospital tank and fill it with aquarium water, then treat the fish in that. You can add a thin layer of sand to the hospital tank and some plastic plants for shelter. Have an airstone, heater and small filter if possible. If you don't have a spare filter you can change all the water in the hospital tank each day and retreat the tank after doing that. Use water from the main tank to refill the hospital tank before retreating it.
If the main tank is not big enough to refill the hospital tank completely, then half fill it with tank water and top up with dechlorintated tap water.
If you use a hospital tank, work out the volume of water in it before treating.
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You can still do a daily water change on the main tank for a week to dilute any disease organisms in the water and reduce the chance of the other fish developing anything. After a week of 50% water changes you can go back to once a week water changes.
If you use a quarantine tank and refill it each day with tank water, you will be able to do a water change on the main tank each day and also on the hospital tank.
-----------------------
The white patches on the body could be related to the damaged eye and short dark barbels but it is probably coincidence. The fish could be weak and this would make it more prone to developing infections, whereas the other fish in the tank aren't getting sick because they are physically stronger.
-----------------------
Any medications can harm fish so you need to follow the directions on the packaging. Fortunately most fish medications have 2 or 3 main ingredients (Formaldehyde, Malachite green, Methylene Blue) and they are relatively safe for fish as long as you follow the directions on the packaging.
The Malachite Green is for protozoans, Methylene Blue for fungus, formaldehyde pickles everything.
If you get a broad spectrum fish medication containing the above ingredients, it will treat the catfish for bacteria, fungus and protozoans. The Malachite Green shouldn't be necessary but if that is in the broad spectrum medication then it is fine.
--------
Sulpha/ Sulfa based medications can also be used and are safer for all fish. Triple Sulpha/ Tri Sulfa are normally available at most pet shops. Sulpha based medications will treat most diseases and can be used at full strength on catfish.
Sulpha based medications normally get treated every few days and if you monitor the water quality for ammonia or nitrite, you might be able to do a water change every couple of days rather than each day. However, if you get an ammonia reading, then do a full water change and retreat.
-----------------------
You can either treat the fish in the main tank or move it into a quarantine/ hospital tank. Due to the rocks and curved front you might be better off using a 40 litre plastic storage container for a quarantine/ hospital tank and fill it with aquarium water, then treat the fish in that. You can add a thin layer of sand to the hospital tank and some plastic plants for shelter. Have an airstone, heater and small filter if possible. If you don't have a spare filter you can change all the water in the hospital tank each day and retreat the tank after doing that. Use water from the main tank to refill the hospital tank before retreating it.
If the main tank is not big enough to refill the hospital tank completely, then half fill it with tank water and top up with dechlorintated tap water.
If you use a hospital tank, work out the volume of water in it before treating.
-----------------------
You can still do a daily water change on the main tank for a week to dilute any disease organisms in the water and reduce the chance of the other fish developing anything. After a week of 50% water changes you can go back to once a week water changes.
If you use a quarantine tank and refill it each day with tank water, you will be able to do a water change on the main tank each day and also on the hospital tank.
