Yes.. it lowers PH.Docsoldlady;2679490; said:Oh I am considering this. Does driftwood really lower ph? We have horrible hard water in my area. Pix don't have anything for scale I hate to ask but roughly what size are these pcs? Rough estimate is fine. If it helps I am considering pcs for 2 of the 30 gallons I have (the small pcs) and the big pc I would like to go into my new 75 gallon once we re-silicone it. Phew longer than I wanted it to be.