In December look into a fishpond and looking at the fish I always think to myself,
'Rather you than me mate.'
For you the fish keeper it is one of those times when there shouldn't be too much to do. Let sleeping worlds slumber. It is when things begin to warm up that the trouble will start and if you have not been keeping up with your 'housekeeping', problems will soon rear their ugly heads.
If there does look as though there is sickness in the pool and it may be just one or two fish then you may want to treat them indoors. I have just sent a reply back to one reader with a fungus/bacteria/white spot problem on his largest fish. He had done a 'one third partial water change', which is one method of relieving what could be an emergency situation. It adds oxygenated water and reduces the level of toxins. I hope he wont mind if I reproduce the reply here because it seems quite appropriate to the potential problems of the season and something to watch out for.
'Many fish problems can be treated with proprietary treatments from aquatic stores, but first of all there are other things to ensure to prevent this happening again or for the spread of the disease. Fish catch diseases when there is some other form of distress weakening their immunity. They are in fact usually secondary infections due to another cause.
Check your water quality.
If there is any imbalance try to do something about it. It may be a population problem, over feeding in cool conditions, over feeding in hot conditions, dare I say - a dirty pool, surely not! A chemical imbalance caused by concrete in or around the pool or even bad tap water perhaps creating a high pH, (A high pH exaggerates the effect of any ammonia or nitrites in the water. Nitrates are not too much to worry about.) Also the disturbance of Herons or other animals make life stressful.
Your partial water change was the right thing to do in the circumstances. Add pool conditioner or a conditioner that stimulates the helps the fish maintain their protective mucous layer.
Then treat the disease. If it just the one fish with the disease then you can treat in a hospitalising tank separately. In this way you can guarantee you get the dosage right. You can ensure the patient gets well fed with high quality food and the treatment chemical is not wasted. Oxygenate well as many treatment reduce the oxygen level.
If you decide to treat the whole pond then keep the fountain going. Do not mix treatments especially salt with any proprietary treatment.
Pond Salt at 3% or 3grms per litre in a bath for 10minutes at time should do it. This is a good all round bacterial remedy. Otherwise treat with a general bactericide
It doesn't sound like the classic 'white spot' or 'ich' which is caused by a parasite (look for twitching or scraping behaviour). If it is this it can easily be treated with a general parasite remedy that must be kept up for 7 days to kill off all the bugs at different stages of the life cycle. However it is always best to treat for bacteria at the same time as treating for parasites since bacteria are the inevitable secondary infection after an attack.' Peter May
