Pond Zyme liquid concentrate

Posted this in the Organics thread and probably should have put it in here. I have a tub of Pond Zyme and I usually just add a pinch at a time but was thinking for measuring purposes as well as activating the enzymes would it be better to pre dillute in a storage bottle to make a liquid concentrate and then use that as my additive. I would use a scoop for every 500ml which would come out to 5ml a gallon hopefully. Not sure about the storage life of the product. Was thinking of throwing an air stone in there during storage.
Anyone else using this method or have any thoughts?