Using old stumps in cichlid tank

[Charles99]

I was wondering if it would be safe to use some old stumps from shrubbery in my fish tank. I removed the bush(evergreen spruce) probably five years ago and the stumps has been sitting in my backyard. 

[Ron]

I've often thought about collecting my own wood as well for display. Here are a few concerns I see about using it in a cichlid tank.

• It's going to float, so you'd need to find a way to keep it down.
• Depending on what specific types of cichlids you're keeping, the decomposition of the wood may drive the pH the wrong way. The wood will passively make the water more acidic. If you're keeping discus or angelfish you'd be fine, but if you're keeping africans I would shy away from it. That doesn't mean small piece is a problem, but I'd limit the amount of wood. Frequent water changes or passive buffers (limestone, etc) would help negate this issue.
• Tannins will discolor the water. However, water changes can help dilute this problem.
• Depending on location/origin, any chemicals in the wood may cause a problem.
• Spruce in particular is a softwood. Sometimes they can produce small hardwood-like sections, but it's going to decompose and fall apart at a faster rate than other options would.

[Charles99]

Thanks for the quick reply, the sun has bleached the wood white and I thought it would look great in an aquarium.

[Marty]

I agree with pretty much everything Ron said.

I would look for a hardwood (like oak) if you can find it so it lasts longer.  Get yourself a tub and soak the wood in water with some bleach added over a few days at least to kill off bacteria or any nasties you don't want in your tank.  Then you want to rinse thoroughly and soak again to make sure the bleach is gone.

If you have any doubts about the safety of the wood, you might consider a cheap "guinea pig" in the tub for a while before adding the wood to your display tank.

If the wood isn't sinking, a good way to keep it on the bottom is to take a piece of slate or ceramic tile, drill a hole in it and use a screw to anchor it to the wood.