usage of old collected fix..

Hello!

I had an unfixed sheet of 4x5 that was trash and it came to me to test to see how long it would take to clear in the 5 gallon tank where I have been putting my used fixer before it was made safe to dump..

The tank has about 2 gallons of Ilford Rapid Fix right now.. It is a mix of 1+9 and 1+4 dilutions of fix from paper or film from the past 4 months...(only 1 type of film and 1 type of paper) I usually dump my fixer into this tank feeling that its not nearly used up.....it is a 5 gallon tank with a spigot and a floating lid..

the sheet of film cleared fully at about 45seconds and it was obviously transparent at about 25-30 seconds..... this is way below my normal fix time I am wondering, assuming the fix is relatively contamination free, what would the problem of using this fix for anything other than not-so-important work, if that , be?

I wouldn't use it for prints, but for film just process for twice the clearing time and you should be fine. Discard when the fix time is double what the spec sheet recommends, that is into the steel wool bucket.