Hydro Water Question!

how often should i change the water in my DIY hydro system? im a noob

What kind of hydro rig, Aero, drip, flood table?

like this but with a pump inside n a halo dripr on top of the hydrotons

DWC in single buckets? 7-10 days is what I do, but you should keep them topped off with fresh water during the week.

If your running just a 5 gal dwc then i would change out every 7 days to keep thing nice and clean.
if you were changing out more water i would say every 2 weeks. Are you using anything to combat
bactiria?