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Re: [APD] RO/pH question

Quoting Andrew McLeod <thefish at theabyssalplain_freeserve.co.uk>:

> A quote off this (http://www.lenntech.com/pH-and-alkalinity.htm) page:
> "Did you know that the pH of Coca-Cola is about 2? And did you know that 
> it is useless to measure the pH of RO-water or demiwater? Both demiwater 
> and RO-water do not contain any buffer ions. This means that the pH can be 
> as low as four, but it can also be as high as 12. Both kinds of water are 
> not readily usable in their natural form. They are always mixed before 
> application!"
> Basically RO water has effectively no buffering capacity - it is 'dead' 
> water with almost nothing in it, which makes it very reactive and 
> susceptible to huge pH swings from a tiny change in acidity or alkalinity. 
> To prepare RO water for use, simply add an appropriate buffer such as 
> Seachem Equilibrium to your requirements.

Sorry, now that I think about it that was a really stupid question. I always 
associate a drop in pH with lowering your KH... of course that is because I am 
adding co2. If I were adding something alkaline, the lower the KH the higher 
the pH would go. I was just thinking of the role of KH in my situation, not the 
actual definition of buffering capacity. You are right, after reconstituting 
the water, the pH dropped. There must have been something alkaline that caused 
the pH of the unbuffered water to spike. Thanks.

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