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Re: KH

Karen writes:

> I have an extremely low KH level (1) in my new 30 gallon tank.  There's no
>  plants in it yet; just water, florite, and gravel.  I lowered the PH from
> 0
>  to 6.0 with Seachem's Acid Buffer.  This lowered my KH to 1 and raised my
>  to 11.  How do I get the KH back up, and is there a better way to lower my 
> PH?
>  (I want to keep Cardinal tetras in this setup.)

In order to get pH down, you must also get KH down.  Trying to raise the KH
will invariably lead to a rise in pH.  KH, in the simplest terms I can think
of to explain it, measures the chemicals which will interact with the H+ ions
that make water acidic.  In the process of interacting with the H+ ions, it
eliminates them, driving the pH value up.  I haven't tried any experiments
yet, but I suspect there is an actual correlation between acidity and
alkalinity that one can detirmine with some regularity what you will end up
with pH-wise when you push the alkalinity up to a given KH level.

I will probably illicit a response from Dr. Morin here, but IMHO, these fancy
acid buffers and discus buffers and whatnot are ill-conceived chemically, and
cause more problems than they solve.  You have ended up with a GH of 11, or
something in the neighborhood of 190-200 mg/l of some +2 ions, probably a of
Ca and Mg.  This will not be to your tetras' liking at all.

If there isn't anything in the tank yet, I suggest you try the following:
Drain the tank completely.
Refill with tap water and check KH, GH and pH again.  If you aren't the same
as your tap water, drain and try again, because there is still some Acid
Buffer in there.

Now.  What is your pH?  What is your KH?  You can lower the pH by a couple
simple methods.  But your KH will go down with it.  But that's okay, your
tetras will like the low KH better anyway.  It will just require a little pH
monitoring on a frequent and faithful basis.

Method 1- stuff some sphagnum peat in the toe of an old nylon stocking.  It
will lowere pH, kH, and GH, making your water a lot like the soft acidinc
water that cardinals are found in naturally.  If the yellowing of the water
irritates you, add some carbon to your filter.  This will take out the
yelllowing, but will also take out some of the micronutrients your plants

Method 2- Use a good, non-phosphate pH adjuster like Aq. Pharmacuticals'
pHDown.  Follow the directions.  Measure again after 24 hours.  The pH will
probably have gone back up, and will do so until the alkalinity has been "used

Method 3.  Buy a quart of muriatic acid at your local hardware store.  This
stuff is around 30% hydrocloric acid in water.  Measure three cups of water
into a one quart or larger glass jar with a plastic lid.  Then slowly add in
one cup of muriatic acid.  Now you have a whole lot more pHDown for a whole
lot less money.  It is around 7-8% HCl. and very strong, but stable.
Experiment carefully to detirmine how many drops of "homebrew" it takes to
move your tank's pH a given amount.  And always wait 24 hours and test again.
The existing KH will cause a certain amount of "bounce-back" until the total
alkalinity is low enough to allow for the acidity adjustment you are trying to

Appreciate that chemistry in a "living" tank of water is very complex.  Adding
Acid Buffer without knowing what it is, only complicates it worse.  Keep It
Stupidly Simple.  Anything that can gauarantee to hold your pH at a given
point over time has to have stuff in it to really screw up your tank,
interfering with the natural chemistry in your system.

Bob Dixon