RO systems.

[jean2]

There are plenty of good RO systems on the market - Spectrapure, Bulk Reef Supply, AquaFX and others. I'd suggest you get a RO system with one (or even two) DI canisters. The extra cost is minimal. Gallons per hour and the particle size the sediment filter will catch are factors to consider. And the unit should come with a pressure gauge, and a TDS meter is nice to have.

I use the 5 gallon water bottles often seen used on office drinking water dispensers. The ones with the handles built in are easy to handle and they are sturdy. I'd think the 5 gallon buckets sold at Home Depot would be a hassle and prone to spill for adding water, but are useful for water changes & other things. For water changes, I use a 15 gallon "garden tub" with rope handles. If you have trouble lifting a 5 gallon container (about 35 pounds) to fill the tank, a pump & tubing can be used to move the water from container to tank.

Yes, you want to add the water FIRST, then the salt. NEVER the other way around. On your FIRST FILL (ONLY), you can add the water directly to the tank, then the salt mix, letting the pumps mix the two. It's probably best to add 5 - 10 gal. of water, then the appropriate salt mix, test the salinity, and repeat until filled, adjusting the water/salt ratio as needed if necessary. But you can never again add salt directly to the tank once it has live rock and/or animals. For future water changes, you'll mix your water & salt in a seperate container with a circulating pump (heater set at tank temp is also recommended), let it mix for a day, then add it to you tank.