We have already just had a section on this matter; suggest that you look it up, as its got some very good info in it. I am a new person in this area myself and i don't know much about it at all. I do know a fair bit about saltwater swimming pools though.
Rgds ian
Ian is right; read the thread called "Live Water? Need info on pumps" under Railway Design. This topic has been thouroughly discussed in the past few days.
Tom Trigg
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