[rsivertsen]

As far as detergents go, there are horticultural detergents that can be used to treat scale and mealy bug infestations, but it is recommended that these plants be rinsed off afterward with pure water (distilled or RO water).

There are a lot of problems with tap water, depending on your location, aside from the usual chlorine and even fluoride additives; which may NOT be removed by just household filtration systems. The usual dissolved mineral salts can be harmful to a lot of plants, not just CPs. My tap water has killed ordinary houseplants in about a year. During the cold winter months, I have used glass (Pyrex) lasagna trays by my heaters to add some humidity to the air, and within a few months, the edges become frosted with mineral deposits that are very difficult to scrub off!

One day, I left the house with the shower nozzle dripping a drop every few seconds, and by the time I got home that night, a blue-green streak on the white shower floor showed how much dissolved copper ions were in my tap water. Copper in almost any form is extremely toxic to plants, and is often used as an algaecide. If you water the plants with tap water, and let it dry out between watering, these things will accumulate in the pots until a toxic level is finally reached and the plants seem to suddenly drop dead for no apparent reason.

Since I started using Distilled water (or RO water), even the sensitive plants seem to be flourishing year after year, in the same pots.

- Rich