"Do not worry about chlorine in the water." I would defer to your experience with chlorine.

However - you knew that was coming ;) - our municipality started using choramine. They didn't bother to tell anyone. They just quietly added it to the list of things in the water for the annual water report.

When does that stuff break down if not exposed to a water treatment? Is it even safe to use with killie eggs?

It must not be in a very great concentration (a novelty because there is so much other "stuff" in there) since one can rinse black worms and leave them (the worms, that is) in it while they sojourn in their blue boxes in the refrigerator.

I expect though that one day somebody in the water department will change the device adding chloramine, throwing in more drops per unit and the worms will be dead in the blue box. That has happened in cities along Lake Michigan, especially after heavy rains. As usual on something like this, I hope I'm wrong.

The mix for the eggs is about 9/10ths RO water (first run through a carbon block). I imagine using "treated" tap water for the other 1/10th isn't quite as dangerous as the "worm water."

I found the dipstrips for water quality that I had used and retested out of the tap. I have a hardness of 150-300 GH. I am unsure of the accuracy of these and when I travel to town I will take a sample into the petstore and have it tested. My alkalinity is way up as well and pH is about 7.8.

Here is an update. I have 1 killifish fry that has hatched yesterday 1/16/2011 and 1 egg that is developing and appears to be getting close to hatch time. I had a second batch of eggs in a different container that all fungused up. I used the fungus guard by jungle in both containers. I am at a loss at what causes some to be ok and others to deteriorate although the 2 that had developed were left in the mop for a week in a bag in a drawer. Maybe that is the key to success.Will attempt to recreate the scenario with the eggs that are in the mop today. Thanks all for the advice!