Milky Rapid Fixer?

I'm new here, so I'm not sure if this question has come up already or not. I looked around, but didn't see anything.

I work in my school's B&W photo lab. Tonight we were mixing our Kodak Rapid Fixer as usual, and both jugs turned out milky. The whole jug.

Part A and Part B were mixed together first, then the water was added. The fixer has been mixed like this before, but with no problems.

We are wondering if maybe the water temperature could have affected the chemicals. The water is usually cool, but this time it was quite cold.

Any suggestions on why our fixer is cloudy/milky?

Thanks for your help!

The acid made sulfur precipitate out. I usually mix the acid into the water first to dilute it then put the fix in, really minimizes this kind of thing.

Usually, but not always, the solution will clear with further vigorous mixing. If it does, the fixer will be OK.

Always mix the part A to volume, then slowly, while stiring, add the part B