Salt nutes all have the same salt compounds made by big chemical manufacturers. GH, FoxFarm, Jack's, Scott's Miracle Grow, etc they all just buy them and blend them together or buy them already blended by the manufacturer and relabel them. All the synthetic cannabis-specific nutrient lines with 10 different additives are just marketing hype to get your money..... IMHO anyway.
Just look at what is in the blend you will use to be sure it covers all the required macro and micro nutrients.
If you are using RO water, then you'll need to supplement CalMag. If you're using tap water, it should have enough CalMag between the water supply and what is in the GH nutrient mix.
Test your water supply pH and TDS/EC. My water is 7.9pH and 200ppm TDS. My plants do fine with that. I use ascorbic acid (vitamin C) for pH down purchased in 2lb containers on Amazon. After I make the mix, I use it to drop the pH to 6.2 to 6.6 range. That takes about 2 teaspoons ascorbic per 5 gal of nutrient mix.