Advanced question

[danny zubot]

How long is long though? Long enough to negatively effect corals?

[midgetwaiter]

It would depend on the temperature of the water and the exact amount of chlorine, etc. My opinion, by the time you have mixed salt completely it should be gone. Small amounts of water added for top up wouldn't make a difference.

If it makes you feel better go ahead and treat your water. It's probably a good idea, DeChlor and such things are cheap and you never know what the city is going to do. In certain situations they do boost the amount of chlorine they add so better safe than sorry. You can usually predict when they're going to do that and personally I can smell the difference easily so I'll take action when I need to.

There's just no way that this is the reason for your friend's problem though, the chlorine doesn't stick around that long.

[danny zubot]

I wasn't aware that chlorine evaporated that quickly, or that Calgary doesn't add chloramine to their water.

I personally use RODI water because of all of the other nasties that are found in tap water. Such as heavy metals. I have noticed a positive difference in my corals because of it, and it tastes better.

[Pescador]

Besides chlorine and high TDS there are some other inorganics that could maybe build up.

Inorganic Substances
___________Unit____ Calgary Water_________ Limit
Aluminum -----mg/L ------0.013 - 0.214 -----------0.1
Arsenic -------mg/L ------< 0.0005 ---------------< 0.025
Cadmium ------mg/L ------< 0.0005 ---------------< 0.005
Calcium -------mg/L -------39.8 - 69.9 ------------no limit
Chromium -----mg/L ------< 0.0005 - 0.0016 -------0.05
Copper --------mg/L ------< 0.001 - 0.003 -------< 1.0
Fluoride -------mg/L --------0.62 - 0.80 ------------1.5
Iron -----------mg/L ------< 0.100 ---------------< 0.3
Lead ----------mg/L ------< 0.0005 ----------------0.01
Magnesium ----mg/L --------10.6-18.1 -----------no limit
Mercury -------mg/L ------< 0.00002 --------------0.001
Nickel ---------mg/L -----< 0.0005 - 0.0011 ------no limit
Potassium -----mg/L -------0.461 - 1.636 --------no limit
Sodium --------mg/L -------2.24 - 7.84 ---------< 200
Zinc -----------mg/L -----< 0.001 - 0.003 -------< 5.0

Sorry for my crappy table.

[danny zubot]

Yup, there's a few in there that I wouldn't want building up in my water.

[mark]

do those water changes...