WATERRO AQUARIUM 100G-H1812-DI reverse osmosis system (capsule-type membrane) WATERRO AQUARIUM 100G-H1812-DI is a compact reverse osmosis system specially designed for freshwater, marine and reef aquariums where exceptionally pure water with a very low total dissolved solids (TDS) level is required. The integrated deionisation (DI) stage removes the remaining dissolved ions after the reverse osmosis process, providing exceptionally high-purity RO/DI water for sensitive aquarium ecosystems. The system uses WATERRO Inline QF 2.0" capsule-type filters, which effectively reduce mechanical impurities, chlorine and other contaminants, protecting the reverse osmosis membrane and extending its service life. Primary water treatment is provided by the WATERRO WR-1812-100 reverse osmosis membrane with a capacity of up to 100 GPD, while the final stage DI cartridge completely removes residual minerals and ions, producing exceptionally pure water for aquarium use. The system operates without a booster pump and storage tank, making it simple, economical and easy to install in locations with sufficient water pressure. The compact design with a capsule-type membrane and inline filters ensures convenient maintenance and quick filter replacement. The WATERRO AQUARIUM DI series is an excellent choice for aquarium enthusiasts and professionals who want to provide their aquariums with stable water quality and ideal conditions for fish, corals and other aquatic organisms.