If you are starting over, I'd recommend buying an RO/DI system and just making your own salt water. It'll be wayyy cheaper and wayyy more convenient in the end. If I had to go to the LFS and give them money for water to lug home every time I needed to do a water change or to fill of the quarantine system I'd probably just end up shooting myself instead of dealing with the aggravation.
Also, by the Dr. Fosters and Smith price, nutri sea water costs $6.14 a gallon! That is absolutely insane. You can get the value RO/DI system (like from BRS for example) with dual inline TDS meter from BRS for like $150 bucks at group buy price, and then it just costs you filter replacements every year or so (like $2 for the sediment filter, $10 bucks for the carbon block, and then you can replace your DI resin as needed for like $10 bucks or just regenerate it for nearly free. Your RO membrane will probably need replacing at the 3-5ish year mark, but it's tough to say). It's 40-50 dollars for a bucket of salt to make 160 gallons, so giving it the benefit of the doubt, by my calculations you break even by about 50 gallons of water -- less than 1/3 of the way through your first bucket of salt and includes the cost of buying the RO/DI system.
Lets say you use just fill up your tank once and change out 5 gallons per week for a year (not including quarantine, emergency water changes, all the water needed for curing/cycling and everything else that might come up). In your first year, you will have used very conservatively 320 gallons. Including the cost of replacing the filters at the 6-12 month mark and buying the system and the buckets of salt, it will cost you about $275 to make the water. The same volume in Nutri sea water will cost you almost $2000.
