Happy New Year fellow reefers I have a wee problem, a fellow reefer gave me his 6 stage aqua-safe system but I want to replace the filters before using them. My issue is the resin container does not have a replacement cartridge in it he just has the resin in the container and I do not know what the replacement cartridge looks like and I have no idea where he is. I could really use some suggestions. Even tried to find the manual but with no success.