wrote on Aug 13^th, 2012 at 7:38pm:

John Thanks for the reply to this thread. I use a swimming pool version of chlorine plus a carbon particle filter and monitor the ph & Cl levels so it is fine for us. As you say you can smell chlorine if there is a blast of water into a bowl, but not otherwise My concern with chlorine is only about it reducing the effectiveness of the septic tank (where all our tap water goes). Do you think that is a reasonable concern? I am not sure how the Cal option works  and what levels it needs to be effective. It is the traditional method in many parts of Europe and I hoped it would not have the same impact on our septic tank. Any thoughts? Cheers

I don't think it will be too much of a problem in the septic tank, after all, the water ging into it is a small volume in relation to the tanks volume. The water in the tank will have been standing for some time and there will be plenty of time for any chlorine to evaporate and drop to very low levels. Raising the levels a bit shouldn't make much difference at all.

The lime is an option but take into account what I said earlier - AND that if there is any left in the bottom of the tank when you refill it, it will be disturbed and will  need time to settle out again before you can use the water. The time needed will be determined by various factors such as volume, depth, amount of lime present, etc. It isn't possible therefore for me to say how long will be needed. You would need to test the water before use using a test kit.

hope this helps.
John.