Like most hydro growers I started with beneficials and all of the expensive add-ins. I spent years adding and adjusting the system trying to 100% prevent root rot or blooms in the reservoir. No matter how hard I tried or how much work I put in, shit still happened.
Since I switched to HTH shock treatments 4 years ago I haven't had a single issue. The winter to summer change doesn't worry me any more, I've had my lung room AC fail and the water get to nearly 80F and still didn't have a problem. I've been preaching the benefits of a sterile reservoir ever since. (And I'm still using the original bag I bought on Amazon for $10.)