The Science of It

[sleepers]

Hi all. I find myself asking dumb questions on this fourm about water care mostly because I don't understand the science behind water levels. I know there three major things we measure are pH, water hardness and alkalinity. Yes?

Does anyone has really good descriptions of what these really are (obviously, having taken high school chem, PH makes some sense to me) and how they actually work in a tank environment?

Thanks! You Aussies are cool.

-Ian

[goldenpigeon]

the ph value is the alklinity or acidity in the water.

[vishy]

Hey,
Correct me if I'm wrong but pH is the amount of hydrogen(acidic) or hydroxide(alkaline) ions dissolved in the water. Hardness or gh/kh are all something similar and have something to do with salts dissolved in the water.
Matt

[Merrilyn]

pH or the power of Hydrogen is the measurement of acids or alkali in the water of your aquarium. With 7 being neutral, any measurement below 7 will be acidic and any measurement over 7 will be alkaline.

Acids are always being added to the tank in the form of fish waste, fish foods, decomposing plant matter, and the end product of the nitrogen cycle in your bio-filter. It is therefore normal for the pH in the tank to slowly become more acidic.

The degree to which a solution maintains its pH when acid is added is termed the "alkalinity" of the solution. Related terms used in reference to aquariums are "carbonate or calcium hardness", and its German equivalent, "KH or dKH" which refer to the amount of "buffers" in the water, which determines it's alkalinity.

Soft water, with a low reading of dKH or KH is more prone to pH crash. Buffering the water with crushed oyster shell or shellgrit will keep the pH more stable.

HTH.

[Dee]

Hi Merrilyn,

Thanks for the informative post, I never knew Nitrate contributes to the lowering (acidity) of PH value ... very intresting. Is there any down side to using KH powder to increase the KH value as opposed to using oyster shells/shell grit ? Apart from KH powder being almost instant and shell grit being slow release.

Cheers,

Dee :)

[Merrilyn]

Dee, nitric acid from your bio filtration is another acid that is constaantly pumped into the water.

The problem with using KH Powder is that the pH will bounce back again, sometimes after only 24 hours.