Let's fix this. Here's 500ml of concentrate this will make 2.5L - 5L working solution.
Here is what Ilford say:
ILFORD RAPID FIXER is a non-hardening, easy to use, rapid fixer. This versatile chemistry is supplied as a liquid concentrate and is suitable for all black & white film and darkroom paper fixing in both manual and machine processing applications.
A 5-litre bottle of RAPID FIXER concentrate makes enough working strength fixer solution to fix 600 x 135-36 black & white films or 2000 x 20.3x25.4cm (8x10in) resin coated (RC) prints or 1000 x 20.3x25.4cm (8x10in) fibre based (FB) prints.
RAPID FIXER must not be used with fix hardeners. Please refer to the technical data sheet for mixing instructions and fixing times.