RO Water vs Tap Water (Edmonton)

[Beverly]

I'm in Edmonton and a month ago set up a 10g using tapwater and Prime. Even though the rock is still curing, I do weekly water changes, making sure to siphon out the crud that accumulates on the tank bottom. I top up with old-fashioned kalk mixed with RO water purchased from Zellers. Mainly softies will go in this tank, though I might try sneaking in a BTA. The light fixture that came with the tank kit holds a pair of household daylight compact fluorescents which, I believe, emit the equivelant of 120 watts of conventional light.

When I was in the hobby a few years back, I used nothing but RO/DI in our tanks ranging in size from 28g to 180g and felt I was doing the right thing. With this 10g, though, I wanted to go very low tech with low startup and operating costs. As I don't have a lot of experience using tapwater in a reef, I don't feel qualified to direct you toward one path more than the other.

You can find out more about Edmonton's water at Epcor Water Quality Reports.

According to this Water Hardness Scale, Edmonton's water appears to be on the border between soft and slightly hard.

HTH

[RGS88]

Out of curiosity, how much is the RO water at Zellers (or other stores in Edmonton)?

[Beverly]

At Safeway, they have the smaller (about 3.5g to 4g), disposable containers for about $5.00. At Zellers Northgate, reusable 5g is about $5.00 with a $10.00 deposit for the first container. It will take me months to use the 5g I have for top ups, but if I used store water for my entire tank and weekly 25% water changes, I'd definitely buy an RO/DI unit. Using tapwater gives me lots of leeway to do larger water changes than I would normally do with RO/DI, though.

Really, there is no reason you can't start with tapwater, then upgrade to an RO/Di system at some later date. A few large water changes on your tank would pretty much reduce the tapwater ratio close to 0% quite quickly.

BTW, Edmonton's water is treated with chloramine which is a compound made of chlorine and ammonia, and it's more stable for water treatment than chlorine.

[bignose]

Paddyob's tanks is running with tap water treated with prime.

There is 2 treatment plants here in Edmonton each will have different water parameters. Check their water test results on the city of Edmonton's website, I've seen it before but I haven't checked for quite some time.

Personally I use ro/di but you CAN use tap water.

[asylumdown]

My 90 was run on tap water in Calgary because I had no where to put an R/O system in my last condo. It's true that there is the chance a freak event could happen and tap water could nuke your tank, but to be honest, if something like sewage or untreated water, or some sort of heavy metal accidentally gets in to the municipal water supply I'm of the opinion that our tanks should be the least of our worries. I drink that water.

In reality, those sorts of events are probably not something you need to worry about on a day to day basis, and as many people on here have demonstrated, tap water is generally fine. However, just because it's probably not going to nuke your tank in a one time freak accident doesn't mean that tap water is 'ideal'. Not for the big bad fears, but for day to day annoyances. There is significant seasonal variability in the quality of our water, it's always top notch from a human consumption point of view, but from a reef tank perspective, it could be good sometimes, and not so good others. I'm not sure where edmonton's main water source comes from, or what regions it travels through to get there, but Calgary's drinking water starts in the mountains and thankfully travels a pretty short distance before it gets to us. As a plus, Calgary's mountain water is actually pretty hard, which can be beneficial for a reef tank. As a minus, the mineral content isn't always constant, so reef specific salts would sometimes lead to solutions with sky high alkalinity when mixed with tap water, and other times it would be spot on.

Also, there was a distinct seasonal appearance of certain types of algae. In the spring I noticed I was constantly battling diatoms, I assume from all the silicate that the snow melt was carrying down from the mountains. In the summer, I learned to not do a water change within a few days of a major rainstorm (which made June a very tricky month), as cyano would explode if I used post-rainstorm tap water. Again, I'm making an assumption, but I think it's because right after a heavy rain the nutrient content of our tap water probably spikes.

So yes, it can work, it's probably not going to kill your tank, but if you end up with mysterious algae problems or unstable water parameters, you're never going to be able to totally isolate any one specific variable or cause with the wild card of tap water in the mix.