That has been my experience and conclusion as well. Many people are not aware of this unless they own an aquarium, but many water districts and municipalities are now using chloramine (a chlorine/ammonia compound) which has even greater persistence in the water distribution system, to the point where neutralizing chemicals are vital if the water is to be used in an aquarium. (water which is simply chlorinated can be detoxed via aeration) The greater 'half-life' of chloramines translates to better results for floated seeds, IMO, although in the long term, I believe that is it potentially damaging to plants - especially containerized plants that are not subjected to the flushing effects of rainfall. Our local water district made the change to chloramine about 10 years ago, and I noticed a simultaneous decline in the health and vigor of my container grown plant - they appeared to be drought-stressed, even though they were being heavily watered. When I found out about the change in water chemistry a few years later, it all began to make sense. As a result, I'm looking into the practicality of ammonia detox products designed for use in water gardens, as well as means of collecting rainfall. Thanks for the excellent dissertation, Lee. Ken East S.F. Bay Area, Ca. USDA Zone 9 -2°C to 38°C