This is my first posting on the APUG Forum, so please be gentle. I've had a darkroom for about the last 35 years, but been out of using it for probably 15 years. I decided to jump back in and I have to say I'm a bit surprised by a lot of what is no longer available. One of the first developers that I've purchased is Photographers' Formulary Divided D-76. Part "B" for 4 liters is 240 grams of borax and the balance distilled water. I've tried twice now, but the borax keeps coming out of solution. The second time reheating the mixture in a microwave well above the 125 degree temperature necessary (according to the instructions). I also filtered the mixture through a coffee filter to be sure no undissolved borax got into the storage container. I've emailed Photographers' Formulary for help, but received no response. The only thing that I am wondering about is the storage temperature. My darkroom is in the basement and it gets into the low to mid 60's this time of the year. Any suggestions would be appreciated.