I have been room temperature tray processing a number of 8 x 10 and 10 x 12 prints in Kodak RA-RT chemistry using a developing time of two minutes. The liter I am working with right now has had 22 or 23 prints (mostly 8x10) run through it and the contrast of the prints has started to rise quickly with the colors starting to look a little "plastic". The first 20 prints looked OK. Is this an indication that the developer or blix is reaching exhaustion? The paper I am using is Kodak Royal "Digital." It's been working well till this contrast issue came up in the last three or four prints. As a test I went back and printed a small piece of Edge and it has the same higher contrast. Is it worthwhile to add a pinch of sulfite to try and extend the life of this batch or just toss it now? I have more stock chemistry to mix so it's not a problem to make a new liter. My main reason for asking is that I would like to know if this quickly rising contrast is a way to tell that it's time for a new batch of developer and blix. In reading the "Darkroom Cookbook", Steve Anchell writes about rising contrast as B/W paper developers move towards exhaustion due to bromide buildup and I am wondering if the same sort of thing is happening here?