Getting ready to buy Dry ferts but need to know what is what.

Guys, I currently use seachem fertilizers for my plants but thanks to a friend, now I know that Greg Watson is much, much cheaper.

So I'm getting ready to make an order and I need to know what is what and what I should be buying:

Iron Chelate-Is this Iron?
PMDD Pre Mix-Is this Flourish Comprehensive?
CSM+B Plantex-No idea what this is, anyone?
Mono Potasium Phosphate=This has to be phosphate right?
Barr GH Booster=What?
Calcium Sulfate=
Calcium Chloride=
Potasium Sulfate=Is this potasium
Potasium Nitrate=Is this Nitrogen
Calcium Nitrate=
Calcium Calbonate=Is this Carbon, Excel?
Magnesium Sulfate=

If anyone can answer feel free please.

I also saw that they don't have instruction on how to mix the ferts with water. Any help would be greatly appreciated.

Hater