United Chemicals Yellow Treat 2 Mustard Algicide, 2 lb, YT2-C12

Yellow Treat 2 from United Chemicals is a mustard algicide supplied in a 2 lb container. It is sold for mustard algae, which is a different problem from the common green kind and is usually treated on its own terms.

What mustard algae looks like

It shows up as a yellow to brownish dust on shaded walls, steps and corners, often on the side of the pool that never gets direct sun. It brushes away in a cloud and then reappears in the same place within a day or two, which is the usual sign that you are dealing with mustard rather than green algae.

Dosing

Our record for this product carries the name, the container size and the barcode, and nothing else. It does not state the active ingredient, the dose rate, the pool volume treated or a contact time. Read those off the label on the container and follow it rather than working from any figure quoted elsewhere.

Working alongside the treatment

Brush the affected surfaces before and during treatment so the growth is exposed rather than sheltered under a film, and keep the pump and filter running so the water turns over. Anything that has been in the pool, from brushes and poles to floats, toys and swimwear, should be cleaned or replaced, because mustard algae travels back in on gear just as easily as it spreads through the water.