you see the blue tube on the side? its a drain tube. it shows u your water level in the res and when u want to change u just tilt it down and your res empties out then u simply pour fresh nutes or whatever straight back in the top over your roots. very simple. only downside is the res is kind of small which is why i created my own system.
its a combo four waterfarm pots with a remote recirculating res. my next grow should be off the hook stay tuned.