I mixed up a 3.5 gallon tank of Xtol, which I use straight for processing sheet film. Actually a wee bit more than 3.5 gallons as I used 3-5 litre mixes. Anyway, after about 14 sheets of 8x10 (various type of b/w film) the solution is looking cloudy. The developing action is just fine, and I have only had the developer mixed up for about 5 days, and I use a floating lid and a cover for the tank. Is the cloudiness anything to be concerned about? My other common developers: D-76 and HC-110 do not get cloudy in tank use.