Tap water for QT?

[OregonReefer]

I got to thinking today... Is there any reason one couldn't/shouldn't use tap water for the QT?

With as often as I'm doing water changes on the QT it would sure be nice to not be going through so much RO water

[Ron Reefman]

Kind of depends on what's in your tap water, doesn't it? If it's good enough for the QT why not use it in the DT? I know there is a big difference, but once you start down that slippery slope...

I prep 25g for a DT water change, then, rather than doing a big water change, I do little ones. The water goes out of the QT. Then I make that up with water from the DT. Then I make that up with the new water. Good for the QT and good for the DT all at the same time.

[OregonReefer]

As far as the quality of the tap water last I heard we have some of the best water quality in the US here.

There is Chlorine added but that's easy to take care of. Straight from the tap I get a TDS reading of 44...

Down the road your method would probably work well for me but right now my bio-load is so low (1-3" Lawn-mower, 1-2.5" Diamond goby, 1-Skunk Cleaner and 8-small hermits) my water changes wouldn't be enough water to get me through between changes... I'm only doing 10g EOW right now and the few corals I have (3-small SPS frags, a two head Frogspawn and a silver dollar sized green leather) don't put a dent in the CA, ALK or Mag

Of course I wouldn't want to go with tap for any coral QT but right now it's 2 small clowns and a Kole (the Kole is about 3" long) in there so my 20g QT can get pretty messy within a few days

[lordofthereef]

If you are quarantining fish, you are likely ok. You don't REALLY need to worry about phosphates and silicates in a QT of fish or inverts. I usually have my QT so dimly lit that no algae ever really gets a chance to grow, at least not in the levels it can/will grow in my display without immaculate water.

[MuffsAbby]

The only issue I see would arise if you plan on using Prime or a similar product to de-chlorinate the tap water, whereupon you would then need to consider potential interactions between Prime and any medications you might want to use in your QT. For example, I've read on this forum that you shouldn't use Prime in combination with cupramine or copper.