I might be able to get hold of a Cibachrome tank (11x14" size I think) -- which is the biggest I am likely to need anyway -- I've been doing RA4 at home successfully for a few months now.

I've been using trays though.

I was wondering -- there's no reason not to use a Cibachrome tank is there? Just roll the paper up and pour in enough chemical (dev, stop and blix) at the appropriate times and I can then do the chemical bit in daylight/normal light.

Are these tanks 'light proof' like daylight film dev tanks? Or would i need to switch off lights between the stages to change the chemicals?