Could you explain what you mean by a pH conditioner? I'd rather not guess at answering.
As for the wood, yes, it may affect the water chemistry but not usually to any significant degree. Wood, like other organics, very slowly releases tannins, and this acidifies the water and thus the pH lowers. But this is only one of several factors in the equation. The GH (general hardness) and KH (carbonate hardness) are part of the pH "triangle" and the KH acts as a "buffer" to prevent pH fluctuations. You are not likely to see any substantial lowering of the pH by wood, and quite possibly none at all.
Byron.