Kieran I feel bad for your plants...they don't need water everyday that's the biggest noob mistake and not PHing your water...noob mistake number 2... you're a bad grower. Advanced nutrients are garbage nutes to begin with and all nutes work in a wide range that doesn't mean you shouldn't PH your water so your plants can absorb the nutes at a better rate...
I bought AN for the first time last grow, had plenty left over so im using them again this grow. I did it just to see if people like yourself were right or if the AN guys were right and it worked great. I havent tested ph of my feed since week 3 of veg on my last grow, I am currently at week 6 of veg on my current grow so thats roughly 20 weeks of growing without a ph pen. I can feed with distilled water with a ph of about 7, ro water with a ph of about 8, or my tap water with a ph of 9.4, it all ballances out with ph perfect. I use php sensi grow that was. $17 for 2 1 ltr bottles and php connisseur that was $24 for 2 1 ltr bottles, no ph up/down, no calibration solution for my pen, no lockouts & no precip in my bottles. Coco is not in any way like soil, it is soilless, soilless growing is treated the same way as hydro. Do tell me about your negative results when you used AN kind sir. I have never had a bad experience with any nute line, they are all the same shit but I will say that not ph'ing, as simple as it is, is great.