Hi gang, did search, but no show...

(quick intro question... is this a CC's "owners club only", or other RDWC setups also welcome? new to these parts!)

I run an RDWC system similar to CC's (Alien Hydroponics), first time round, going great, coming from coco its a natural evolution.
I have read a gzillon DWC diaries, closely mimicking the best results I saw - like any newb would - during the years up to now.

Everything hydro tells me to start seeds/cuts as low at 5.5, which in fact gives me the best result. Then slowly and gradually move the scale until the flush, where I am at 6.4. This has also been my de-facto schedule for coco with great results, and almost all dwc I've seen, though many start at 5.8.

So I am truly confused when I followed a grower's diary (on another site, but he lingers around here too) in his first UC run, and he started at pH 6.3 or abouts. He has years more experience, so I thought he was having an aneurism. I didnt get into much debate, I really thought it was a brain-fart or was a typo for 5.4... didnt think more about

So I was showing the UC product PDF to a friend who is looking into buying an RDWC kit, and it hit me... CC themselves recommend to start at 6.3 and end 5.7!!!

This is the exact opposite of everything I've ever learnt. I am in shock actually? what gives?

thanks in advance