CO2

Components of an RO/DI System

Sediment pre-filters: 5 microns → 1 micron (retain solid particles)
Activated carbon prefilter (GAC + CTO): removes chlorine/chloramines (protects the membrane)
Reverse osmosis (RO) membrane: 75–100 gpd (gallons per day) for household use
DI (deionizer) cartridge: ion exchange resin → reduces TDS to 0 ppm
Storage tank
TDS meter: measures the purity of the produced water

Production: 75 gpd ≈ 280 L/day. The process generates "reject" water (3–5 times more than the amount produced) → which is of good quality for watering plants or cleaning.

Maintenance: Replace membranes and cartridges based on usage and the TDS of the produced water.

AUTOMATION AND CONTROL

Aquarium Controllers

Apex (Neptune Systems): The most comprehensive and popular system. It controls the entire aquarium via an app. It measures pH, temperature, salinity, and oxygen levels, and controls smart plugs, dosing pumps, and more.

GHL Profilux: a European alternative, highly professional

Raspberry Pi + ATO: A DIY Solution for Electronics Enthusiasts

ATO (Auto Top Off)

It automatically replenishes evaporated water with fresh water. This is essential in a marine system to maintain stable salinity. It uses a level sensor in the sump.

Brands: Tunze Osmolator, AutoAqua Smart ATO, DD H2Ocean

Dosing Machines

Peristaltic pumps that dispense liquids (Ca, KH, Mg, fertilizers, bacteria) in precise, programmed amounts. Brands: GHL, Kamoer, Jebao, Bubble Magus