alkalinity and PH

[salineh2o]

If Alkalinity is On the PH scale.

Then why do I have to test for alkalinity seperately

[Xirxes23]

Alkalinity and pH are related, but not the same. It is possible to have high pH and low Alkalinity. To put it simply: pH is a measure of the ratios of H3O+ to OH-, and Alkalinity is a relative measure of a number of different synergistic factors.


Check out the chemistry forum and the Chemistry posts by Randy Holmes Farley in the last sticky topic, and there is a thread in there relating Alkalinity to pH.

[salineh2o]

So what is the negative result of low alk.

[Xirxes23]

low alkalinity will have a detrimental effect on calcium uptake in both fish and corals, leading to problems with skeleton formation and eventual death in calcium carbonate forming corals.

[salineh2o]

what is the correct alkalinity level for a reef tank in meq/l?

[b_mattias]

around 2.8 - 3.8 is good.