Abstract: A method of providing water suitable for irrigation use includes feeding pre-treated water to an electrodialysis apparatus, treating the pre-treated water in the electrodialysis apparatus by selectively removing either one or both of monovalent anionic and monovalent cationic species from the pre-treated water while retaining either one or both of multivalent anionic and multivalent cationic species to produce a treated water stream having a lower ratio of monovalent ions to multivalent ions than the pre-treated water, and directing the treated water into an irrigation water distribution system.

Abstract: A method of providing water suitable for irrigation use includes feeding pre-treated water to an electrodialysis apparatus, treating the pre-treated water in the electrodialysis apparatus by selectively removing either one or both of monovalent anionic and monovalent cationic species from the pre-treated water while retaining either one or both of multivalent anionic and multivalent cationic species to produce a treated water stream having a lower ratio of monovalent ions to multivalent ions than the pre-treated water, and directing the treated water into an irrigation water distribution system.

Abstract: Describes a chemical feeder that supplies treating agents, e.g., calcium hypochlorite, to a liquid stream, e.g., an aqueous stream. The chemical feeder is operated in a substantially flooded condition to provide a useful and safe pressure feeder, and optionally uses cyclonic flow to be relatively self-cleaning. One or more tablet canisters are utilized within the substantially flooded interior of the chemical feeder, and expose the lowermost tablets to the turbulent flow outside of the tablet canister. A substantially uniform chemical distribution rate over tablet life is provided by the chemical feeder.

Abstract: Describes apparatus for dispensing a sanitizing chemical into a swimming pool. The apparatus is a container having a closed bottom, a lid with a dispensing opening, and a plate with colored markings that is larger than the dispensing opening and freely moveable vertically resting on the bottom of the container. The plate has a specific gravity of less than 1.0. In operation, the container is filled with solid sanitizing chemical, e.g., calcium hypochlorite, and placed in a skimmer basket associated with the pool. When the sanitizing chemical is completely dissolved by water pumped through the skimmer basket and recycled to the pool, the plate floats to the top of the container where it can be observed readily to indicate that the apparatus needs to be refilled with sanitizing chemical.