Yes, you should put wood in a bristlenose pleco tank. Most care guides treat driftwood as a required item, and bristlenose plecos spend a lot of time rasping on it. The claim that a tank without wood will kill them is not supported, though, and keepers disagree about whether the fish actually digest the wood or just graze what grows on it.
Bristlenose plecos (Ancistrus) are known to rasp on driftwood. Some care guides say the fiber from the wood aids digestion. Other experienced keepers say Ancistrus eat the biofilm and algae on the surface and don’t break down the wood itself, unlike true wood-eaters such as Panaque. Either way, wood is cheap and does no harm, and it gives the fish a place to graze and hide.
Wood also helps in these ways:
- It gives them surfaces to graze, where biofilm builds up.
- It provides hiding places, which these nocturnal, shy fish need.
- It releases tannins that lightly acidify and tint the water. Check your pH if you add a lot of wood to a soft-water tank.
What kind of wood is best for bristlenose plecos?
Aquarium-safe driftwood works. Malaysian driftwood and spider wood are common picks, and many keepers also use mopani, grape wood or cholla wood. Soak new pieces for a few days to a week so they sink and release most of their tannins before you add them.
Don’t use wood collected outdoors unless you know the species and have cleaned and cured it, because some woods rot or leach harmful sap. Pine and other softwoods with resin are a poor choice.
What should you watch for?
- Wood is not a replacement for food. Feed algae wafers, sinking pellets and blanched vegetables such as zucchini or cucumber a few times a week, since the algae in most tanks is not enough.
- Rasped wood looks scuffed or pale. That is normal grazing, not a problem.
- A thin or sunken belly, lethargy or hiding all day point to under-feeding or illness. Adding wood won’t fix them.
- Replace pieces that turn slimy or start to rot.