Abstract: This invention relates to the field of phosphate removal from a body of water, especially in pools and spas. It is an improved method of removal of phosphate from pools and spas by the topical addition with a hand held, hose end sprayer of a phosphate scavenging agent or composition, such as aluminum chlorohydrate and a suitable chemical for pH adjustment, allowing the scavenging agent or composition and phosphate to interact and for the resultant product to settle to the floor of the pool or spa. After twenty-four hours the sediment on the floor is removed by vacuuming. After a second twenty-four hour period any additional sediment that has settled to the floor is removed by repeating the vacuuming procedure.

Abstract: In a cleaning system which uses balls made of spongy material for cleaning fluid conducting tubing a ball collector having a housing with inlet and outlet ports, the outlet port having a strainer screen which allows fluid but not the balls to pass, and an access port with a releasable cover sealed with an O-ring. The cover is of metal frame construction with a transparent center, preferably preferably comprised of a pyrex glass member encased in a metal sleeve.

Abstract: A diffuser for mixing and oxygenating water or other liquid with an airstrip employs a self supporting microporous tubular membrane, arranged in a spiral or grid configuration, with openings between proximate elements which, are at least equal to the diameter of the membrane. Gas, when forced through the tubular membrane, forms fine bubbles which agitate, oxygenate and entrain the surrounding liquid as it slowly passes through the openings. The tubular membrane is flexible and is to be mounted on a manifold which connects it to a source of air or gas, and which may also impart buoyancy or serve as anchor in the liquid.