No problem. It helps if you understand that when you wash film, you are dealing with gelatin that has chemicals absorbed in it. The wash process causes those chemicals to slowly diffuse out of the gelatin. If you use a washaid like Kodak Hypo Clearing Agent ("HCA"), those chemicals are first converted into a more water soluble version. That cuts down on how much washing is needed. In any event, effective water washing requires both time and flow. Unless you first use a washaid, a simple 5 minute wash doesn't provide enough of either - especially if you are using a hardening fixer. If you want to use a water change approach, you need to be sure each change is separated by a period of time which includes continuous agitation of the water. The chemicals need time to diffuse out.