Seal it with food grade polyurathene. You can get this at a paint store, just be very sure it’s food grade like for use on counter tops and chopping blocks. As an additional note, I wouldn’t use wood from the yard unless it was well sealed, it will simply rot over time and won’t take long to do it.
MM
My friend used stones in the tank with his Oscar. I would be wary of wood, especially if it had any prior chemical treatments.
I really wouldnt consider putting wood from your backyard into your fishtank! You dont know what grot and grime is on there that may affect your fish.
If you want to put wood into your tank, buy some bogwood from a fish shop or even one of the resin cast wood sections.
We have a piece of bogwood in our tank as well as a bit of cast root style decoration. Both look lovely, both are safe and neither make the water murky.
Wood is fine in a tank, but it has to be sterilized.
Boil it if it is small enough to fit in a pot.
If it is not, seal it in an airtight clear plastic bag and leave it out in the sun for a few days. This is called “solar sterilizing”
don’t put wood in it
you have to boil driftwood. If you dont, it will release tannins into the water, thats what ur seeing.
You can just boil it for a few hours. Honestly the tanin looks bad, but it’s harmless. In a few week it will all leech out, and a new carbon filter will clear things up.