I do not feel compelled to use the whole bottle, unless you mean eventually. I always make up a gallon stock solution from the one gallon Kodak kit. That's the directions from Kodak. Everyone does that. Then one uses what one needs for each developing session out of the gallon jug of stock solution. Generally, I pour it back into the stock solution, and it lasts a good long time. It was in the mixing up of the stock solution that I erred. I put the hardener in because some of the films I use have soft, fragile emulsions and need it. It was fixer for film, not paper.
This is all reminding me too much of grade school. Yes, it was my mess up. Who said it wasn't? Should have just googled it instead of asking for advice on this forum.
Hi momus:
It wasn't that serious a screw up - lots of us have done worse, and recently too!
But as mentioned above, many (most?) of us don't mix up the whole gallon of 1+3 Rapid Fixer at the same time. In my case, I mix up 1.25 litres at a time (without hardener). I then use that stock to develop my film until:
a) the clip test indicates it is time to discard/recycle it; or
b) I reach 60% (24) of the Kodak capacity recommendation (40 rolls),
whatever comes first.
You could do the same with the hardener.
The advantages of mixing the smaller quantity are:
1) smaller, more easily handled bottles;
2) better storage life for the un-mixed remnants; and
3) it is easier to keep track of 24-40 rolls of use, than something between 96 and 160.
The disadvantages are that you have to measure a relatively small amount of hardener (if you are using it) each time you make a batch and that you need to keep track of a couple of extra smaller bottles.
You can adjust the size of the batch you make - 1 US quart has a capacity recommendation of 32 rolls.