Flushing DWC w/Clearex Q

I plan to flush my DWC with Clearex and I am not sure what to do. I searched and I could not find an answer to my question. (Man, I hate misspelling when I search here--60 seconds is soooo looong.)

Question: When using the Clearex, do I just do a nute change and use plain pH'd water mixed with the Clearex to spec and just leave that solution go and top off as normal? Or, do I do a nute change with Clearex solution and watch the PPM's and then change out to plain water when PPM's stop rising?

Thanks,