[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Acidic kitty litter (was KH Buffering)

On Tue, 11 Jan 2000, Sylvia wrote:

> I was equally impressed by this, as I have to use peat to acidify the water
> for cardinals and neons. I've tried various brands, but filter media capacity
> prevented me from using a sizable enough amount to achieve anything much in
> the line of acidifying the water . . .

Use a low pH kitty litter with caution.  The kitty litter isn't acting as
a buffer.  It's a cation exchanger that releases acid into the water as it
is exchanged for other ions (principally calcium and magnesium) in the
water.  The substrate pH can reach levels that aren't particularly good
for plants.  Also aluminum ion is often part of the acid held by the clay.
With the aluminum ion is released at low substrate pH it can cause
elevated aluminum concentrations in the water.

Aluminum is toxic to plants, and that may contribute to some of the poor
growth that Michael Tipton reported in his original letter.  Probably his
main problem was with low CO2, but aluminum toxicity is a possible

This potential problem isn't limited to certain brands of kitty litter.
If you live in the southeast and want to use some of those nice clay soils
in your tank then you may want to first check it's pH.  I recall reading a
few years ago on a web site at Clemson that aluminum toxicity from acidic
clay soils was a fairly common problem in the south.

Roger Miller