I use a holding tank that is left to sit for 24hrs to get rid of clorine, then use it for water changes. Today I did a water change on some of my Discus fry, I did one of my fry tanks first, then went and did some other things. 1/2 later I notice all the fry at the top gasping. PINIC Mode. I immediatle did a water test, and came up with 2.0ppm Ammonia, Confused by this I tested my Water holding tank, again high ammonia, so I tested water coming out of the tap that fills my hilding tank. Shock horror - positive test to ammonia.
I contacted our local council and was told they would investigate and get back to me.
After a panic treatment with Ammo lock and stress coat to get the levels back to 0, and contacting our LFS to find out what products they had for ammonia, I was told that after the recent bad weather the council may have flushed the water lines.
The cost of this so far is 44 6 week old discus fry.
I will no longer presume that the water coming into the house is good quality.