imo its pricey but not that complicated. if you upgrade his 18 gallon res design to a 40 gallon reservoir, pH and Ppm levels are going to be more easier to deal with it. I let pH swing between 5.4-6.2, out of that it gets correct it back to 5.8. If your strain can take lets say 400 ppm max, that's where your grow work load it gets interesting lol but with stinkbud kiss method its easier.
I use a 1.9L motts jug lol with ro water and nutrients (A+B, Cal Mag), when ppm drop below 250, i will add back to 400 ppm, besides that make your system lightproof to avoid brown algae.
happy growing