drinking water and sodium bicarbonate

[popothemailman]

I use ocean water, because of this I only do a 10% water change per month, and everything is going well. However, about once a week or so I have to add some water to the tank due to evaporation. I use drinking water from one of those water stores, the drinking water has a ph of 7.4 will it be alright if I add some sodium bicarbonate(baking soda), to the drinking water to get it to a ph of 8.2 or so?

[malkore]

Well yes, you can, but ONLY if you're testing the carbonate hardness (a.k.a. alkalinity) in your tank first.

Remember, water evaporates...alkalinity, salt, trace elements...do not evaporate.

If your tank stays at 8.2 with top-offs, and your alkalinity is at the correct range, then there's no need to add baking soda to top-off water. In fact you could end up putting too much alkalinity in there, and driving the pH too high (and then you'll be like the member in the thread above yours with 18-19dKh!)