I have a relatively new darkroom - 3 years old. The darkroom is in the basement, and we are on a septic system, with the inlet to the septic tank above the level of the darkroom. To get the waste water out of the darkroom, the sink drains into a 'laundry tray system' which is essentially a box with a sump pump in it. Recently, the pump stopped working - and it turns out that the problem is with the float switch - a replacement is on order. The thing that has me wondering is the fact that when I opened up the Laundry Tray system, I noticed a lot more corrosion on the metal parts of the pump than I would have expected. My darkroom effluent is probably pretty typical - 99% of it is wash water - I do not send fix or toners down the drain, I do send my spent developers and stop bath down the drain, but I would have thought that they would be diluted enough not to contribute to the corrosion. Has anybody else run into anything like this? Mark __________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.