Need advice on salt and substrate

[Myka]

I'd suggest using Instant Ocean until you find a reason not to. It's cheap and easy to find. I don't like Reef Crystals because the calcium is super high, and I don't think the difference between it and IO is worth the price difference. Both Instant Ocean and Reef Crystals have high alkalinity so that will help you out while you're not dosing. I also like H2Ocean, and have used it for years on my reef tank, but the cost keeps going up on it, and it's now a $100 bucket of salt. It's a natural seasalt though, it's not synthetic. So yeah, just stick with IO for now.

For substrate though, I would not suggest a gravel. I would go with a coarse sand like Caribsea Seaflor Special Grade or Caribsea Aragamax Select. Gravel gets too much gunk stuck in it, and fine sand blows around the tank and makes a mess.

[Simons]

I have used salinity and IO and from the two I feel IO is better from a mixing point of view. It took salinity for ever to mix in comparison at least from my experience.

I have 1 mm fine sand in my tank, I had to strategically place some rock islands to keep it from blowing around when my power heads cycle up, something to keep in mind. I knew that could be an issue, but I wanted the 'white' sand bed look in my tank so I just did some intervention before it became an issue.

I have about 1 inch of sand, so definitely not a DSB, I have heard and read many posts and articles some for DSB and some against. I think if you keep a goby or other sand sifters in your tank like I do, you should not have any issues with whatever you decide to go with.