Moving from city h20 to RO/DI h2o

[glblguy]

I just purchased an RO/DI unit on eBay. I purchased the 3/4" hook-up option and plan to mount it on the wall behind our washer and dryer, since the water and drain is already there.

Question though, I want to get the city water that's already in the tank out, and replace it with fresh RO/DI water.

What is the best way to do this? Had planned to do like 10-20% water change wait a few days do another, repeat 4-5 times. While that won't get rid of everything, that should replace most of it I would think.

Thought I would consult my new found 3reefers first though. Any advice?

[snail]

Hard to say, are there fish in the tank? How long have you used tap? Is your rock stable? Is there a pressing reason to change it out so fast?

[glblguy]

Hi Snail, water has been in there for about 6 months, but water changes done about once every two weeks or so. Water specs are good, although I think my KH is a little high (240ppm or 13.4dKH).

I tested for phosphates, and they are 0, but the tank is full of hair algae, especially on the sand/rocks. So was hoping putting some RO/DI water in there would solve that problem.

There are fish in the tank, 2 clowns, squirrel fish, blue damsel, 2 zerbra snails, mushroom coral, and some polyps...few brissle worms, feather dusters, orthopods, etc.

Just concerned there might be bunch of other minerals and junk in the water that might be keeping my corals/fish from thriving.

[matt s]

If they've done OK so far I'd just let your regular water changes gradually switch this stuff out for you. It'll take longer to get to full RO status but you'd be avoiding the sudden adjustment in their environment. It doesn't sound like what you have is doing any tremendous damage so you don't need to get it switched out quickly?