Re: Aquatic Plants Digest V1 #222

>From: svr at eecs_umich.edu (Steve Robertson)
>Date: Tue, 30 Jan 1996 09:28:43 -0500
>Subject: Gravel... To wash or not to wash?


To tell whether this reddish-brown stuff is really iron, I would try using
an iron test kit on some of the water that the gravel has been washed in.

I have always washed my gravel though.

I would be more concerned about calcium in the gravel though & suggest
you do a vinegar test to see if the gravel might harden your water.

Also, regarding adding weird or nasty things to your water (e.g. the african
violet fertilizer), I've heard that some people really think you should now
let your fish drink Pepsi since the ad's on TV do it!

>From: "Jennifer Orme Van Buskirk" <J.VanBuskirk at m_cc.utah.edu>
>Date: Wed, 24 Jan 1996 18:35:15 +0000
>Subject: driftwood
>say it ain't so!  could my driftwood be buffering my pH?  after
>placing a handful of gravel in some R.O. water, the pH went to 7.6,
>not even co2 could lower it.
>i am planning to replace the gravel with a substrate that will not
>buffer my pH basic.  but before I tear my aquarium down, i decided to
>test everything in the aquarium (ie, gravel, rocks, & driftwood).
>the various rocks I have didn't cause pure R.O. water to change it's
>pH, but the driftwood did.  it went right to 7.4.  could this be?  i
>got the idea that a decaying piece of driftwood would produce more
>acidic conditions.  what up?
>matt van buskirk - in blah, blah, blah, where it's blah degrees

I'm confused Matt - did your gravel or your driftwood raise the pH?
Often gravel will raise the pH if it contains calcium carbonate - test
it by putting some into a glass of vinegar & if the gravel fizzes then
that's your problem.  Driftwood might raise the pH if it was collected
from the sea, but most freshwater driftwood won't.  Some woods with
lots of tannins such as "bogwood" (which is great cause it sinks well)
will actually lower the pH.

But ... it is difficult to measure the pH in pure RO water & something
that causes a change in RO water may not have such a great effect in
your tank since RO water has no buffering capacity but your tank water
probably does.  Are you having pH problems in your tank?

In Madison WI where it's -20, -35 with the wind chill!

Joanne Stevenson-Barry
University of Wisconsin-Madison
Muscle Biology Lab
1805 Linden Drive West
Madison, WI 53706
email:  stevensj at calshp_cals.wisc.edu
phone:  608-262-1066 or 262-1547
FAX:    608-265-3110