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I think plain IO gives you the best bang for your buck. As long as you use a salt mix that doesn't contain any type of organics, i.e. Reef Crystal, Red Sea Pro, etc. you can keep it for long periods of time without any PH's/aeration. Make sure your using RO/DI water.
If you dose your reef, i just go with instant ocean and add any calc that it is lacking, maybe a bit of mag as well. dkh is usually around 9 with the mix.
There is no "best." It's what works for you. I'm very happy with plain old Instant Ocean. Fosters & Smith regularly have a sale for $40 for a 200 gallon box.....with free shipping. Ocean Gallery II also just had a sale for $40 a box.
Regular Instant Ocean here. I use a 30gal tank for my mix station. It mixes constantly and I use what I need and top off as it goes. If I start dumping 5 gals from it starts topping off as its dumping, I add more salt and move on. In theory its been mixing for about 2 straight years without a cleanout and without the slightest bit of precipitation built up. The only time the pump gets shut off is if I happen to do a large water change and it starts to draw air.
I switched from IO to IO reef crystals and I find the reef crystals mix nicely. I have it down to where I don't really need to check the salinity (but I always do). I agree with @downbeach on make sure you are using RO/DI water. Also pick up a refractometer if you don't already have one
I started off with IO Reef Crystals than switch over to Kent Marine Salt. But i do enjoy both product. Buying it in 200 gallon box are abit of a money saver for one pocket.
If you have a fairly new tank that does not consume a lot of alk and calc you may find its hard to get the levels down to NSW levels with IO. You can use a salt that mix to NSW levels then switch to the cheaper IO salts. I had this problem when I first setup the tank.