- --- You wrote: One text that was recommended to me, but I haven't been able to = track down yet, is Spotte, S., Fish and Invertebrate Culture: Water Management in = Closed Systems, John Wiley and Sons, New York, 1979. I've been told it's worth checking out... - --- end of quote --- David, This one is very widely available in the US through libraries. If = your library doesn't have it, it should be easy for them to borrow = a copy through interlibrary loan. Unfortunately someone is using = our library's copy, so I'll just have to wait! - -Susan