Update:
Well the developments are that the slime seems to have reduced on the fish. The water has also gone become milky cloudy. This made me test the water again and I have found that the nitrites are at 0.5ppm (I feel bad coz I must have done the test wrong last time) now I know this could be the cause of the slime and my feelings are that it probably is the problem.
The questions now are what would cause a nitrite spike or small cycle in the tank? There has been no added fish so it cant be that.
So Im guessing that something must have seriously decreased the size of my bacteria colony.
My theories are:
- the overdose of flourish excel would cause that.
- it was the flourish excel anyway, the overdose just made it worse.
- the plants I added somehow gave the bacteria a problem.
When I added the plants I did a 40% water change, gave the tank a good scrub and vacuumed half the gravel but did nothing with the filter. I didnt even remove it from the water.
Any ideas?