tap water
 

Does anyone have success in keeping coral reef tank with just tap water?

a discussion people on here have had many times! yes. i only use tap-water my reef tank is fine! search around and see what you can find.

I use tap water but I'm going to do the ro/di route down the road just to eliminate tds and such from any problems encountered down the road..

I use tap water. Without issue

I use tap water. But also ro/Di but I have success. It all depends on the quality of you tap water. Mine has some crap in it so I try to use ro when possible.

Most area's have ground water test reports. Check out your city page and they should have some. You can see what the TDS is, as well as more tests than we run in our tanks. Most places around here the ground water is good, and the stuff that's actually in there is also in our salt mixes, making it very good. I run RODI because after a couple lead and copper pipes I'm worried about my houses contamination in the water.

I use tap water but the lower mainland has really good tap water under 10 tds

I use tap water too, it fine for my sps but i have algaes

I always had an algae problem when I used tap water. There used to be a guy on here who lived in the N part of Calgary ( different water source ) who used tap water and prime. He had a nice little mixed reef.

Here's the thing. Yes, you can use tap water. Especially in Van, the water is very soft and pretty good quality. You may get nutrients going into the tank to cause algae, you may not.
But with a water distribution system so large, the room for something going wrong, like introduced contaminates, is fairly possible. You wouldn't know it unless it was really bad (I remember Kelowna in 97 had to boil water for a few months) and there was a public announcement. But a mild issue, coming from a broken main near a gas station, could wipe out your whole reef. If' you've got a little nano with 2 corals, maybe you want to take that risk.
For me, I've got thousands of dollars worth of SPS. I'm not going to risk losing it all by using an unknown factor. Our water is really good here too, almost all of the time. But what if?
A RO unit is a couple hundred bucks, tops. Half that for used. I think that's a pretty good insurance policy.
In emergencies, I've used tap water for a water change. Nothing bad happened. No algae. But....what if just once there was a contaminant in the public water that was toxic to corals? That's not something I want to encounter!
Lots of people do it, and I guess it's personal choice based on what your corals are worth and the level of risk you're comfortable taking.
Also, keep in mind that household plumbing does contain copper, and can leech it slowly into your system.