Maybe, you can try a floating lid as to reduce the contact to air ? Claudio Bonavolta http://www.bonavolta.ch ----- Message d'origine ----- De: Peter Badcock <peter.badcock@xxxxxxxxx> Date: Wed, 3 Feb 2010 10:37:46 +1100 Sujet: [pure-silver] Re: Measuring low levels of silver in fixer À: pure-silver@xxxxxxxxxxxxx I've only started doing that, as I found it motivated me to use my darkroom more often as there was about 10-15minutes less set+packup time. I didn't have to pour out, then pour back+wash my stop+fixing trays ! Working FT with a family of seven [1] I don't have much spare time. I put a loose cover over the top of the trays but perhaps a tighter or sealing cover (plastic wrap etc) would bet better. rgds Peter [1] my wife and I, 3 kids+2 dogs On 3 February 2010 10:20, Ralph W. Lambrecht <info@xxxxxxxxxxxxxxxx> wrote: PeterThis is not a good sign. It sound like you need to change the habit of leaving the fixer out open in the tray.