I half assed in trying to build a hydroponic system a few years ago. Looking at this video, i realise how much effort it takes. But it must be so rewarding.
This one is fully automated and remote controlled. If you are willing to make it more manual it is not nearly as complex. Also the bigger the system is the more buffer to have so that changes in water quality are only slow. In a tiny system like that of the video you need to react much faster.
The biggest challenge i faced was getting the pH and nutrient right. The pre measured hydroponics nutrients were only available online to me at a big premium over big bags of similar sounding stuff like NPK, micronutrientes at local stores that sell them for farmers. I read up as best I could, found calculators, weighed and measured doses but I failed and my dear tomato saplings wilted in hours before my eyes.
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