I purchased the tank and cabinetry from a great guy who did the plumbing installation as well. He swore up and down that if I used tap water for the test I would never get the phosphates out of the system, and I'd have all sorts of algae blooms.
He guaranteed the plumbing for thirty days not to leak â€"œ I wanted to fill the tank and test it out while he was still willing to fix any installation problems. So I went with the RO/DI. Figured at that point, better safe than sorry.
By the time I had all of that RO/DI in the system (215 for the tank, 30 in the sump, 40 in the refugium, etc.) adding salt was a small step. I guess we also needed it to set up the PH monitor/calc reactor/salinity meter, etc. Besides, he said that the salt would help seal any really tiny leaks...
So here I am with a tank full of water. On the plus side, the salt actually helped identify a small leak (I never would have noticed the tiny drop of water, but the salt build-up made it easy to see).
On the other hand, figuring out how to get the substrate and background in has been a challenge. But some comments that Zoos offered connected some of my disfunctional brain cells. Between my RO/DI tank, Salt water mix tank, and a wheeled Rubbermaid I forgot I had, I have enough to empty the tank, without flushing it all down the drain.