Les,

As usual, thanks for the thoughtful response. I guess the one big question I
have is can wood bring the PH too low ? And are there kits to measure PH below
6 ?

Thanks again !

Hans

--- In corydorasandmore@yahoogroups.com, Les Mumford <lesmumford@...> wrote:
>
> Ahhhhhh, you have discovered one of the hidden benefitsd to using real wood in
an aquarium. As it sits in the water, the natural tannins contained in the wood
slowly leech out into the surrounding waters. Larger aquariums don't show the
discoloration as quickly as smaller ones, due to the dilution factor. These
tannins do slowly lower the pH of the surrounding water. The longer it is there,
the lower it goes, basically, and doing small changes in a small tank allow the
tannins to build up, where they would be removed quicker in a larger tank with
corresponding larger water changesFish from the Amazon, or some other large
water systems in rainforest areas would appreciate this type of water a lot.
Neon tetras would thrive and breed readily in it, if they were not captive bred
types that have slowly adjusted to higher pH levels. Abrupt changes to the lower
pH ranges can be devastating to fish, even if they are from naturally low pH
ranges. If you do decide
> to add fish, you will not be able to add a lot anyway, due to it only being a
three gallon tank, but slowly accustom them to the water, just as you would
adding them to a higher pH level tank. Or, adding new fish to an existing set
up. Good activated carbon will help remove the tannis, and clear the water color
if that bothers you. The tannins discoloration is just a basic warning to you of
the water conditions. Many people store water in large plastic cans with wood to
naturally lower the pH so they can do their water changes into similar set ups
without disrupting the pH ranges they have worked so hard to get. Many killies,
and wild caught imported fish, and even a lot of the captive bred fish you can
get in shops will only breed in the low pH ranges, and this is one way of
getting it without using a lot of chemicals that really don't work well, or from
using expensive systems like RO units and ion exchange units. They may adapt to
living in the
> higher pH ranges, but they will not thrive, and will not breed, and even if
some of them do breed, the spawns will be very small, or the fry may not
survive. With some fish like discus, it has been proven that harder water and
higher pH ranges cause the egg skin to harden prematurly and before the male's
sperm can fertilize the eggs, soo it looks like a good spawning, but the eggs
just fungus over since they were not viable.
>  
> Fish like actually eat the driftwood, like some of the bristlenose plecs, and
fish that grave on the wood for the small animals they eat from the surface of
the wood, like the very small
> plecs, will help keep the wood in better looking condition, but all wood
placed in water will eventually rot and fall apart, and will need to be
replaced. (except maybe something like ironwood from exotic places). Different
woods used will make a difference also. Oak and some others are better for the
aquarium, as things like pine has that natural pitch which doesn't do well in
water. A friend of mine used to use applewood from his back yard, as he knew it
was not contaminated with pesticides etc.  If you pick up wood, it needs to be
treated to make sure it does not contain parasites, or other bad things, and the
bark removed if present, as it will disintegrate and foul the water quickly. 
Most wood will also float until it is saturated. So if you fetch your own, peel
the bark, and soak it in a plastic trash can or similar, and use a med to kill
parasites etc before using it in an aquarium.
>  
> I hope I got it all in here. If I missed a point, or you have other questions,
ask away. 
>