Instructor shows how to start hydroponic seedlings: adjust pH, saturate rock wool and use humidity dome

An instructor at a Phoenix gardening workshop demonstrated how to start hydroponic seedlings, showing participants how to calibrate and use a pH meter, lower alkaline faucet water to the proper acidity, saturate rock wool plugs and manage humidity and fertilizer before transplanting seedlings to a raft system.

The instructor said, “So we'll walk through how we get the seedlings started and also how we use the the pH meter. So we already calibrated the, the pH meter.” He tested the tap water and reported, “Looks like your water is about 7.7,” then added acid in small amounts and rechecked the solution until “it's about 5, 5.6,” which he described as “right where we wanna be.”

The instructor demonstrated adding phosphoric acid to lower water pH and cautioned participants on safety: “This is the the phosphoric acid, which you definitely wanna keep away from definitely keep away from the kids and the lid.” He said only a “tiny bit” is needed and showed how…