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