Reverse osmosis (RO) systems are very commonly used to produce pure water for saltwater and planted freshwater aquariums. There are a few simple RO accessories that can save you time, save you money and produce cleaner healthier water for your fish.

Adding DI
If you have a regular RO system you should consider adding a deionization (DI) stage. This stage goes after the RO membrane and can increase water purity from 95-97% to 99.9%. If you already have a DI stage, it can still be helpful to add a second DI stage.

Keep in mind that DI resin doesn’t go bad all of a sudden. Instead, it fades and will start letting more waste through and need replacement. If you just have one DI stage, you will need to replace the DI when the resin is still somewhat effective, but not completely effective. With two cartridges, you can run your RO system until your first cartridge is completely depleted, and then move your second cartridge to the first spot and add a fresh cartridge to the second canister. This means fewer DI cartridge replacements, saving you time and money.

For DI add-ons, we recommend the AquaticLife Twist-In Dual Deionization Filtration Unit and the SpectraPure MaxCap D-1 Retro Kit 1 Station.

Auto Shut Off Kits
If you have an RO system, it is common to leave the system filling a container and then forget about it. This can lead to a flood. A shut off valve, such as the AquaticLife Float Valve Kit, can automatically turn off your RO system when your container is full.

TDS Meters
TDS meters let you know how pure your water is. They are extremely useful when trying to determine how well your RO system is performing. There are two different kinds of TDS meters: the dual meters (SpectraPure Dual TDS Meter) and single meters. Single meters can measure the TDS at one point in your RO system and dual meters can measure TDS at two points. Using a dual meter allows you to know how pure the water is after the RO membrane and how pure the water is after the DI resin. The water should read 20 ppm or lower out of the RO system and 0 out of the DI. Higher numbers indicate that the cartridges need to be replaced.

Flush Kits
RO membranes don’t last forever and they can be expensive. Using a flush kit such as the SpectraPure Flush Valve Kit can help your membrane last longer. Turning the valve in the flush kit will send water over the membrane to flush out the debris for a longer membrane life. It is recommended that you flush the membrane for about a minute whenever you make water.

Pressure Gauges
RO systems perform differently at different pressures. In general, higher pressure leads to better performance. Using a pressure gauge will let you know what pressure the membrane is running at and can let you know when to replace your sediment cartridge.

A pressure gauge should be installed after your carbon filter and before your membrane. The pressure should read 50-90 psi. If the pressure drops below this range, it is a sign that either your home has low water pressure or your sediment filter is clogged. Knowing when your sediment filter (aka micron filter) needs to be replaced will allow you to run it for as long as possible. SpectraPure has an easy to install Pressure Gauge Kit.

NOTE: for low water pressure, see the Booster Pumps section below.

Extra RO Tubing
There are many reasons to purchase extra RO tubing. One use is for transferring water to a new tank. If your RO is far from your tank you could run an RO line to the tank. This is much easier than filling buckets with water and then hauling them over to the tank. Some use extra RO tubing along with a Float Valve Kit to fill their auto top off reservoir.

Booster Pumps
Some homes have low water pressure. Because RO systems perform best at higher water pressures (70-90 psi), booster pumps are designed to increase the pressure to your RO system. The AquaticLife Smart Buddie Booster Pump will boost your RO unit’s pressure up to 90 psi. It includes sensors that automatically turn the unit off when the valve is closed and turn the unit back on when the unit starts producing water again. The pump will also automatically flush the membrane periodically, prolonging the life of the membrane.

Upgraded Cartridges
Some RO cartridges perform better than others. The Spectrapure ZetaZorb Cartridge filters sediment down to .2 microns and can last 5 times as long as other sediment filters—meaning it can last most people two years or more. SpectraPure also makes a specialized Silica Buster High Capacity Cartridge, designed to specifically remove silica—one of the first pollutants to get through normal DI resin. It is also designed to have a 33% higher capacity than normal DI cartridges.

Upgraded Fittings
Many fittings that come with RO systems are cheap, easily broken, and prone to leaks. Swapping these fittings out with quality fittings will ensure a good seal and fewer leaks. We prefer the AquaticLife RO Fittings because they include locking clips to ensure that the seal is secure and water tight.

Liquid Level Controllers
The dream RO system set up for many aquarists is an RO system connected directly to the tank’s auto top off. This can be risky, but can save you lots of time if done right. The SpectraPure Liquid Level Controller is specifically designed to connect an RO system to a tank. The controller includes an extremely reliable pressure sensor and solenoid valve to turn your RO unit on and off. We recommend you use the controller along with a SpectraPure Float Kit placed above the desired water level for redundancy.