few novice hydro questions

say you have a DWC setup with netpots in like a rubber made bin, when you go to change your water what is the best way to remove the remaining water in the reservoir without disturbing the plants too much? do yall just take off the netpots/plants and dump it out? or have a open close valve at the bottom or something like that?

also in a flood type system do you need an airstone or something to give the roots oxygen when they're flooded? or do you not in a flood/drain system where the roots are not submerged in water 100% of the time?

anyone have any good hydro diagrams? I get how most setups work and all Im just not that technical and dont see parts of things and things that have to be done and why clearly.

I'm a noob, but I'll tell you what I do. By accident I happen to have this little pump with a chuck that you hook up to a drill. Tube goes into my set up and the out tube to the bucket. The great thing is I can control the speed so when I get down to the end I can slow up and tilt my reservoir.

bubbler systems that use buckets are the easiest to change and maintain. I have grown soil and also ebb and flow which is with a grow tray that fills up around the plants. Now we have a DWC grow and changing the nutrients is as simple as dumping out the old nutrients and scrubbing with a sponge and warm water! Then add fresh water, then nutrients. You need aeration in any grow in the nutrients and especially in a DWC grow where the roots drop down into the nutrients and stay there for extended amounts of time. Check out my grow in my signature I think you would benefit a lot in understanding how hydroponic setups work, especially bubbler/ DWC

If you have a second tub you can just move the whole lid with plants and rest it on the second tub.

Or you can have 2 rez and move the plants to the second one and you are back in business in like 3 min at most. Then clean out the last one you had been using and it will be ready for the next time.

No you don't need to have air stones but it's a good idea even in an ebb & flow system. The extra oxygen and added bonus of having the air stones keep your nutrients mixed up is a good thing too.