I got some free chemistry a while back that included about 5 boxes of kodak rapid fix. I just mixed some today and noticed a yellow cake at the bottom of the container. I have shaken,stirred until it became a mass of of small yellow pebbles (almost sand) diluted with the proper amount of water and the "sand" has yet to completely disolve! Should i go ahead and use it? Wait for it to all disolve(maybe never) or throw the whole mess away?