I have to say that after experiencing top-down recirculation feeding that fertigation in general is not the way, here’s why:
When the nutrients flow through the media back to the tank at high flow rates, they flow through the rhizosphere in a manner similar to NFT. I heard a phd horticulturist call it a micro-NFT effect.
By feeding this way for ten minutes the plants drink all they need and you can tell by the runoff, when it comes back lower. If it comes back higher you are heading for nutrient lockout.
Most importantly, when the nutrients sit in the tank after picking up biologicals from the rhizosphere and you have a nutrient mix tuned for recirculation you will find dense bubbles indicating enzymatic activity which provides for a healthier, higher-yielding plant. Drain-to-waste feeding does not allow for this effect.
Fertigation also is not that suitable for such a mix which has 8 parts. Every fertigation system I’ve seen has a 5 part mix at most, usually 4, and lower yields comparatively. This is where a Master Grower makes his and your money, mixes the nutes once every feed week according to the needs of the crop.
Also, if you go with fertigation I advise you to get a service agreement or training for periodically cleaning and servicing the mechanisms preventatively to keep them from fouling and throwing your mix off.
While your specific configuration may not be suitable for recirculation for a few reasons, you may want to introduce a tea to get that enzymatic action. That can’t happen with fertigation either.
Yeah, i crack up when people post ads for “Master growers” in fact maybe @Growernick had a topic on this not too long ago. Growing Cannabis is super simple. Only needs three things. I see soo much un needed stuff going on in grows it amazes me. Sometimes i wish we could strip it all away, and let these guys learn how to grow with only their hands, some good earth, water, and sun. That is all you need.