I have a printo that I used for b/w as well, for almost two years or so I ran it set up continuously--changing the chemistry every week to week and a half. EventuallY I quit using it because one of the energy therms died, but that's another story...
at any rate, I used Ilford 2150 chemistry in it--both the older version and the newer one which mixes at 1:4. Mine is just two tanks--dev & fix--so I ran it set up for RA4 with 45 seconds each tank, at about 80 degrees F. 2150 usually runs in a 2150 machine at 95 degrees at around 15-20 seconds per tank, so this is no big deal really. 2150 kits cost about 40-55 bucks, they've had a price increase over the years, so 55 is probably where they're at now. You can get about 4 to 5 weeks out of kit broken down for a printo.
The chemistry is used to exhaustion, unreplenished and the entire kit would handle about four to five gallons of working solution. in a 2150 machine, you'd get two weeks or 1000 8x10s whichever comes first.
I usually ran no more than about 150 8x10s a week if that--mostly I used smaller sheets or made contacts with it, so usage was never really a problem. I also left the chemistry in the tanks continuously as well--occasionally I'd pop the lids open overnight, but I never had a problem with oxidation really. When I changed chemistry--I drained it out, refilled it with water and ran it for a few minutes, then drained that & refilled it with fresh chem. I used it liked a mini-2150 machine. Every three months or so, I'd pull out the racks and put them in a clean tray and hose them down, and then do the cleanout cycle back in the machine and set it back up with fresh chemistry.
so it's 90 seconds more or less---I used tongs to pick up the damp print from a tray I had near the exit--then I washed for 2-4 minutes with a tray siphon, then I ran the prints through an Arkay RC1100 dryer I have. my dry to dry time was about 7 minutes or so. A little longer than the 80 seconds in a 2150, but not bad really....
My only criticism of the machine is that as a modular unit, you have to make sure it is very level, since the chem is right near the tops of the tanks. if you overfill even by the slightest bit, or if it's not level, then it can leak. I would have liked the machine better if it was constructed in one piece to be honest, but it's a neat little processor--very versatile and well made.
hope this helps.
KT
