You should do some searching here. There are some threads about this very topic. You will get vast opinions based on a variety of factors. I'm sure that for some, it becomes habit to use a certain salt mix.
I'll chime in on this.Allot of people will say that most salts are made by the same manufactuer.In the case of reef crystal and instant ocean this is true. If you are new to the hobby it is best to consider expense and demands of your aquarium.Looking at what expected trace elements is the first place to look.Some advertise 440 calcium levels others high alk dkh levels.I preffer Britewells neo marine just for the fact that it's very consitant.When I test a fresh batch it is as advertised.When I used other brands I found the alk very incositant which makes doaseing much more dificult and the swings are hard on livestock.Truth is many people have their brand that has worked for them well.Best advise is to chose one and stay with that brand.If you have a preffered LFS it would probably serve you best to use what they use because it will be available to you when you need it.
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