Storage of used acid and alkaline fix

I've swithed from using an acid fix to an alkaline fix for my film processing. I keep my waste chemicals until I fill a 5l bottle and then dispose of via my local community darkroom. Can I add waste alkaline fix to my half full bottle of waste acid fix and store until it's full? I seem to vaguely remember something about not mixing acids & alkalines from my chemistry lessons at school!

Mixing them neutralizes the acidity or alkalinity. No problem.

Guy, as you live in London you might want to check out Silverprint. Martin Reed has now announced that Silverprint now has the means of recovering silver and will pay or discount against purchases depending on the portion of silver recovered

His range of materials and overall prices aren't bad either

pentaxuser

Thanks chaps