R/O vs tap water

[sam]

First I'd like to just say that I'm new to the forum and have found it to be very helpful so far....lots of great posts.

I'm debating whether to set up a salt water reef tank. I've have a heavily planted tropical tank for about 3 years and looking to ad another tank to my house. There are still a few lingering questions about SW.

I've read conflicting information about the use of tap water in reef tanks. What's the concensus....do you have to use RO water or is tap water OK? One thing I read said you could use tap water for your initial water but use RO for make up water and water changes.

I live in Dallas and have been testing our tap water for quite a while now for to my plant tank. Phosphates and nitrates are just about 0ppm.

Thanks for any info you can provide.

[slipknottin]

You might want to do a couple additional tests of your tap water. Silicates, copper, and ammonia tests would be good. Do you know if you have chlorine or chloramine?

You should also test your tap water at various times throughout the year, as seasonal differences can change water chemistry quite a bit.

You can use tap water if it tests ok in all of these tests, RO water wont be any improvement if you have no problems with your water now.

[OrionGirl]

Yep--can't emphasize enough the importance of tracking water over a couple seasons. Outside of chlorine, my water is great...Until spring time hits. Our water comes from reservoirs, and the spring runoff brings all sorts of nasties in with it--serious bacteria builds up, then is killed by treatments. This then turns to sludge and nitrates--they can get over 50ppm! Yelch.

So, we have a filter system we run all the time. It's just easier to not worry about it, since the one time you don't test is the one time it will kill an entire tank.

[VoodooChild]

If your town recently (3 years ago) installed some giant water treatment plant, do you still have to worry about the water conditions?

[OrionGirl]

No way to say with testing the water source. All water treatment adds things to the water. How this will impact the tank depends on what's being added. Think about chloramines--they're very popular and an cause serious problem for an aquarium, more so than chlorine. Chloramines won't gas off overnight like chlorine will. Getting the test results from your utility will help, but testing it yourself for ammonia/nitrites/nitrates is still important to track seasonal shifts. The report from the utility represents either a snap shot view, or an aggregate one. Not the best for seeing what's happening each time you run water for a change.

[rgmatzke]

I have very poor city water with very high ph levels over 8.6. I just purchased a RO system and the PH read at around 7.0. I don't know if this is good, I have read that it should be around 8.1 to 8.4.

[Satchmo]

Once you mix in your salt, the pH will rise to where you want it.