How measure PH?

[hillbillyreefer]

Buy a pH meter. It'll pay for itself with use anyway. Get some calibration solution when you order it and calibrated every couple months. It's just easier, quicker and probably more accurate.

[untamed]

You know...I ran my first tank for twelve years and never really measured the pH. I don't think one should attempt to change the pH anyway. Especially NOT if you are not 100% dead accurate with pH measuring. Besides, to get a truly accurate reading of what your tank is doing you would need to measure ever hour for a 24hr period because there is a daily cycle.

So..go ahead and measure pH. It's fun. But don't try to change it!

Control your Alkalinity (and Ca), and the let the pH do what it does.

(Hypocritical advice as I am currently attempting to control my daily pH swing using my Kalk reactor...but I think that is different...)

[Delphinus]

^^^^ I second what untamed said.

One exception, you DO want to measure pH of a reactor's effluent, and forget trying to use test kits for that. You need to know the difference between 6.6 and 6.7 and 6.8 and you really need a meter for that sort of thing. 6 years ago I tried dialing in a reactor using pH test kits. That lasted about 3 weeks. Bought a meter and never looked back.

[Brent F]

I'm not looking at controlling PH. I'm trying to determine which product to use to raise alkalinity. Some, such as baking soda, lower PH while many comercial products raise it. I was trying to determine whether a product that raised PH or lowered it would be beter to use.

[untamed]

Originally Posted by Brent F

I'm not looking at controlling PH. I'm trying to determine which product to use to raise alkalinity. Some, such as baking soda, lower PH while many comercial products raise it. I was trying to determine whether a product that raised PH or lowered it would be beter to use.

Holmes-Farley did an excellent article on the affects that alkalinity supplements have on pH. This should answer your question.

Here's the article:
http://www.advancedaquarist.com/issues/may2002/chem.htm

[Brent F]

Thanks, Untamed. The article you posted explains why most additives increase PH while baking soda lowers it. I was using the calculator at http://home.comcast.net/~jdieck1/chemcalc.html to find a product to increase alkalinity for my tank based on the effect on PH and where my PH is.

This whole post started because, without knowing my PH, I wasn't sure whether to use baking soda or a comercial product to increase alkalinity (or maybe both?)

[untamed]

...and I sometimes find it difficult to figure out what the commercial products actually ARE. They are often mixes of many chems so their affect on pH is hard to predict.

I've gone to sodium bicarbonate when I need to dose.