I am using distilled water from Walmart (88 cents). It actually cost more then buying RO/DI water (69 cents) from my LFS but is just a little more convenient for me and also don't need to worry about buying a bunch of 5 gallon jugs to fill up with the water. That can be another $70 or so expense just to buy the jugs.I don't have a refractometer yet. Petco is the only LFS and I don't think they sell one. Sioux City water is terrible and I wont be using tap. I am looking into buying a RODI unit... however with school starting I just wanted to get my tank set up and the cycle started. I've read forever about RODI units and it looks like they are about 130 on the cheap side. Would I be able to get away with filling the tank with RODI water from petco or distilled water until I have enough money for my own unit. I would rather start off the right way that's why I am in no hurry to rush into starting. But its all just sitting there and I cant wait to begin! LOL.
Also, I have dead coral that's been sitting in a bucket covered with a plastic bag. Do I need to do anything before putting it into my tank besides rinsing it with tap water? I've read bleaching... but to me that just sounds like a bad idea no matter how thoroughly you rinse it.
RO/DI is definitely said to be the best though. Not sure how it truly differs or what it does or doesn't offer that is found in distilled water. Researching it gives you a lot of different opinions.