Changing DWC Reservoir. How often?

I change mine every sunday always check your ec I change mine once it goes over 2 ill redtop it with ph water 5.3 to 5.5 and a little calmag and h202 for the roots

You dont have to change it so often as long as your keeping your water cool. I kept mine at 62° With no root issues at all. Although you dont have to change it so often, you changing it and cleaning the system once a week is best if your not familiar with plant problems, because it can create problems not changing out so often and you need to be able to read your plants. By changing it once a week your also supplying everything the girls want once a week. Which is were you got to know what your plants want cuz they will take up the npk at different ratios and leave the water deprived of certain nutes that it fed more on.. plants look good cheers.

There are beneficial microbes that can help keep your tank in check over time.. or run a little h2o2 etc.. one way or another, you can control it, not unlike an aquarium or a pool. chemicals or microbes.. It'd still be wise to clean it out of course.. i don't know the best maintenance plan in that context, lol.