Hi all, please forgive my ignorance but I am new to using anything but Kodak Powder Chemicals. I have never used liquid concentrates for processing so I'm clueless. I picked up my first Ilford product, 500ml bottle of their Rapid Fixer. Ok, so I understand I should use it at 1:4 for film and 1:9 for paper. My question is, how do I mix this 500ml bottle to get 1:4? Do I mix it with, say, a gallon of water to get 1:4 or does a gallon get me a stock concentrate which must then be further diluted 1:4 (or 1:9)? Any help for a liquid novice would be greatly appreciated. Thanks in advance!!!