You're dead on, D. It's not snake oil, they do have a place in your grow room. They let you raise phosphorous and potash levels in your grow without adding more nitrogen. The owner of AN has had some pretty offensive things to say about GH over the years, 99% of which is BS. AN has some good products but I won't do business with assholes. So next time you're in your hydro store, tell your guy I said he's full of tomato paste that was growing in shit.
AN's P and K is no different that GH's. And I've used KoolBloom for years and can assure you it does NOT affect the taste of your weed.
Most of GH's (and other vendors) additives have a place and purpose and will help total yield, but as a general rule, I find GH's recommended dosages are off by about 50% (too much) and their bloom feed schedules by 35 - 50% too much as well.
Diamond Nectar, KoolBloom and Floralicious Plus I'm total sold on. I won't grow without them.
ArmorSi and CalMag - don't leave home without them, ESPECIALLY IF you're using RO or have naturally soft water.
FloraNectar and FloraBlend? I use them, but might play with leaving them out one day. I'm just not sure enough to NOT use them. Sorry me.
If you have the time, look at
@Autotron 's grow thread at starting at about page 3 -
https://www.autoflower.org/threads/autotron-does-hso-uk-cheese-hydro-cob.66293/page-3 I laid out some tried and proven dosages from years of experience that work practically every time.
And kudo's to you for calling BS on your hydro guy!!!