The Versalab print washer is about as basic as it gets - a very tough polyethylene tank, a removable set of dividers, and some hoses. Water use is controlled using a siphon break, though the inlet rate has to be set at a reasonable level to avoid overflowing the tank. I keep mine in a dedicated sink since my supply is subject to pressure variations. Print washing is essentially a diffusion process - as long as the chemical concentration in the wash water is lower than the concentration in the emulsion, the chemicals will migrate to the wash. I live in California, so minimising the use of water is important. This means I usually partially drain the tank, refill, and then let the prints soak for a while before the next cycle. This uses slightly less water than a continuous low flow. The drainage is clean enough to go to the ornamental side of the garden.
The standard 11x14 inch configuration uses a rack of vertical dividers to separate the prints. This works fairly well, though the potential cross-flow between sections does mean that this is best used as a batch washer.
I do not make many prints above 11x14 inches, but I do make 20x16 inch prints on request. The Versalab 11x14 model tank will accept the 16 inch width of the bigger paper with the rack removed. I obtained a couple of pieces of stiff but flexible plastic sheet (PVC) from a local plastics supplier which are 16 x 22 inches. These are formed into two ‘U’ shapes and clamped together to give ‘UU’. The paper is formed into a matching ‘U’ with the emulsion inside.
This allows two 20x16 inch prints to be washed together. Provided the usual precautions of not over-fixing, rinsing well before washing, and using a wash-aid, are performed, the results should meet all normal requirements. The paper does not sit in full contact with the supports, so there is water flow around the back of the print. If I made a lot of larger prints then I would look at either the 20x16 inch or 20x24 inch models, but for my limited needs this adaptation works well.