I know it's a silly question but I'm seriously asking. Before my pretty Susan passed a while back (rest his fishy soul) the only change I made to his environment was the addition of a small piece of driftwood with a anubias rubber-banded to the wood. His water parameters were fine and stable. I'd boiled and soaked the wood numerous times (yes I soaked in conditioned water) and I treated the plant for any parasites or bacteria (even though I bought it from a tube, not from a pet store tank.) I let both of these items soak in treated water for a long time before adding them to his tank, then things quickly went south. The only thing I can think of is a possible hidden parasite or a sudden change in water parameters. I read that the tannin's can cause Ph spikes, is his five gallon home too small to handle even a tiny piece of driftwood? It's no larger than my palm and it's been safely sitting in my main tank for two weeks now after I let the wood dry out for weeks and weeks. I bought a new plant to attach to the wood. I just want to be careful this time, even if I can't have the wood I'd still like to add the plant to his tank to hopefully get it a bit more "natural" looking. If it helps I think the wood is mopani, can't be certain as the label when I bought it simply said "driftwood."