"Rich Conley" wrote in message
...
Is there any way for me to lower my PH...currently around 7.6 without
making my water more yellowish browny collored with tannins? I have some
driftwood in this tank..and that helps...but I want to be sub 7.....any
ideas?

Be careful....

If you go down to say 6.8 at normal levels of CO2 (1-3ppm) you will have a
Kh of well under 1 degree - i.e very close to a Ph crash.

The only way to get under about 7.4 safely is by injecting CO2.

For example...Ph 7.4 & CO2 of 2.4 ppm (about atmospheric) will mean you have
a Kh of 2 degrees.

Once you get under two degrees Kh becomes much less stable in my (limited!)
experience - i.e. it takes a lot less to make it fall towards crash country.

If you were not aware of it there is a direct relationship between Kh , CO2
and Ph. In simple terms, at a fixed level of Kh , if you add CO2 then PH
will fall - take the CO2 out (or more exactly, stop adding it & let the tank
return to atmospheric condition (about 2-3ppm)) and the Ph will rise back to
where you started. If you are adding CO2 then the the PH will be determined
by the amount you add - the more you add the lower the PH will be.

At a KH of 2 deg, if you boosted CO2 to say 15ppm (which would be much
appreciated by your plants and won't affect fish) then you will have a PH of
6.6

OTOH you could start with a KH of 5 degrees, add CO2 to 15ppm & your PH will
be 7.0. Stop the CO2 & let it return to say 2-3ppm & your PH will climb back
to about 7.8.

You can adjust the Kh with peat filtering to reduce it or by adding
something with Calcium Carbonate (crushed coral/limestone/baking soda etc)
to raise it.

Unless you adjust CO2 by injecting it then it will stay fairly constant & in
equilibrium with the atmosphere at 1-3 ppm.

Running an Airstone or excessive turbulence at the surface will tend to
drive off CO2.

Add CO2 during the day will "turbocharge" your plants which will then give
off masses of oxygen. Adding CO2 (within limits) does not affect the water's
ability to carry oxygen for your fish. That is much more sensitive to
temperature.

HTH

rgds

Iain