[jones57742]

IMHO Nothing.

Several species of wood are common in fish keeping due to their aesthetic qualities as well as due the holes and caves which they provide.

This wood has been aged and contains no liquid resins but does typically contain tannins.

The "sticks" which you quoted could be used as "driftwood" by aging (in order to remove/dry liquid resins) and subsequently boiling or aging in water (in order to remove tannins).

TR

BTW
Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins and are typically very acidic.

 

[jones57742]

... Hopefully someone with actual experience with Malaysian driftwood will tell you more about the pH effects.

Folks:

This is a really weird one but true.

I soaked Malaysian driftwood for several months and removed what I thought were all the tannins before placing it in the tank.

Joy: no yellowish tint to the water.

Approximately 3 months ago Chris (the gal I run around with from New Mexico) decided that she would occasionally enjoying seeing air bubbles in the tank.
She placed two bar and one disk air diffusers in the tank.
She also inadvertently placed a piece of driftwood on a portion of and above the disk diffuser.

We were out of town for several days and left the air on for tank water oxygenation in the event of a pump failure.

When I returned home a yellow tint was evident in the water in the sump.

The aeration of the wood had caused the release of tannins which were not removed via the original soaking or the subsequent submergence in the tank water for six months.

TR