SoftPlus Water Softeners Iron Rival Iron Reduction Systems ecoTAC Hard Water Conditioning Systems

Sterilight Cobalt Plus Series Ultraviolet (UV) Sterilizers

Sterilight Cobalt Plus Series UV Water Purifier

The Sterilight Cobalt Plus Series is ideally suited for whole house water treatment to kill bacteria (including coliform and e.coli), viruses, cryptosporidium, giardia, and a wide range of other microbiological contaminants where flow rates of under 31 gpm are required. Given its economical price, UV intensity monitor, and optional emergency solenoid shut-off kit, the Cobalt Plus Series is a popular choice for homeowners with a known contamination problem involving a serious contaminant like e.coli, cryptosporidium, or giardia.

All Cobalt Plus Series units feature a stainless steel reactor chamber, a fire-polished domed quartz sleeve, and a high output Sterilight Sterilume™-HO coated low pressure germicidal UV lamp which can be conveniently changed without interrupting the water flow. The UV lamp provides a 4-log (99.99%) reduction of bacteria, viruses, and protozoan cysts (cryptosporidium and giardia) at the specified maximum flow rates. The Cobalt Plus Series electronic controller features a switchable power supply that automatically detects line voltage between 100-240 volt and adjusts its operating settings accordingly.

The Sterilight Cobalt Plus Series is composed of 4 models with treatment capacities ranging from 6 to 30 gallons per minute.

Applications small home average home all homes large homes
Max. Flow Rate
(UV dose >30 mJ/cm2)*
(30.3 LPM)
13 GPM
(49.2 LPM)
32 GPM
(121.1 LPM)
40 GPM
(151.4 LPM)
Max. Flow Rate
(UV dose >40 mJ/cm2)*
(22.7 LPM)
10 GPM
(37.8 LPM)
24 GPM
(90.8 LPM)
30 GPM
(113.5 LPM)
Water Chamber Material 304 Stainless Steel
Chamber Length 17.8 inches / 45.2 cm 22.8 inches / 57.9 cm 30.7 inches / 78.0 cm 39.4 inches / 100.0 cm
Chamber Diameter 3.5 inches /
8.9 cm
Controller Size 9.4 x 3.2 x 2.5 inches / (24.1 x 8.1 x 6.4 cm)
Lamp Sterilume-HO
Model S200RL-HO
Model S320RL-HO
Model S600RL-HO
Model S740RL-HO
Sleeve Quartz
Model QS-200
Model QS-320
Model QS-600
Model QS-740
Electrical 100-240v, 50/60HZ (240 volt plug is special order, please call us for details)
Power Consumption 35 watts 42 watts 73 watts 88 watts
Lamp Power 27 watts 34 watts 65 watts 80 watts
Inlet / Outlet Plumbing Ports Combo 3/4" FNPT / 1" MNPT 1" MNPT 1.5" MNPT
"Power-On" Indicator Light Has Feature
Audible Lamp Failure Alarm Has Feature
Lamp Replacement Reminder Has Feature
LED Display: Lamp Life Remaining, Total Controller Runtime Has Feature
UV Intensity Monitor Has Feature
Powered Solenoid Output Optional
Switch to US pricing
See Viqua VH410M for replacement
See Viqua VH410M for replacement
See Viqua VP600M for replacement
See Viqua VP950M for replacement
Sterilight SCM-200 Sterilight SCM-320 Sterilight SCM-600 Sterilight SCM-740

*Note: Maximum recommended flow rates based on 95% UV transmittance. Actual dosage depends on flow rate, water quality, and maintenance (cleaning of UV sleeve). UV dosage will be lower when the UV transmittance capacity of the water drops below 95% - if in doubt, select a model rated for a higher flow rate than you actually require. We recommend a UV dose of 40 mJ/cm2.

Feed Water Quality Parameters
Iron 0.3 ppm (0.3 mg/L)
Manganese 0.05 ppm (0.05 mg/L)
Tannins 0.1 ppm (0.1 mg/L)
Turbidity < 1 NTU
Hardness < 120 ppm (7 grains / gallon)
UV Transmittance (UVT): 75%
Maximum Temperature: 104F (40C)
Maximum Pressure: 125 psi

Pre-treatment Requirements:

All UV sterilizers required sediment pre-filtration to reduce or eliminate the possibility that a targeted contaminant could "hide" behind a sediment particle in the "shadow" of the UV light and therefore not receive a full dose of UV light. Accordingly, the manufacturer strongly recommends sediment pre-filtration down to a level of 5 microns or smaller.

Water exceeding 120 ppm in hardness (7 grains per gallon) should be softened to reduce the risk that hard water mineral scale will build-up on the UV sleeve thereby reducing UV light distribution into the UV chamber. Similarly, iron levels exceeding 0.3 ppm or manganese levels exceeding 0.05 ppm should also be treated to prevent staining of the UV sleeve.

Elevated levels of certain other contaminants, such as tannins, can cause a reduction in UV transmittance (the ability of the water to transmit UV light). If the UV transmittance (UVT) of your water is less than 75% after the above-mentioned pre-treatment, activated carbon filtration may be desirable to improve UV transmittance. The majority of deep wells have a UVT of 85% or greater. If your UVT is unknown, select a model with a higher flow rate capacity then you feel you will really require (this will provide a higher UV dose at your desired flow rate), or add an activated carbon pre-filter to your system. We recommend the following pre-filter equipment:

sediment pre-filter for UV sterilizer sediment and activated carbon pre-filter for UV system iron reduction filter
5 Micron Sediment
Pre-Filter Package

excellent overall sediment pre-treatment to 5 micron level
Sediment & Activated
Carbon Pre-Filter Package

sediment pre-treatment to 5 microns and improves UV transmittance by removing tannins and other contaminants that reduce UVT
Iron Reduction
Filter Package

very cost effective iron pre-treatment filter for iron levels ranging from 0.3 to 5.0 ppm

Recommended Accessories:

Sterilight Temperature Management Valve

Temperature Management Valve
The Sterilight Cobalt Plus Series can be equipped with a temperature management valve to regulate water temperature within the unit due to the high output lamp. The Sterilight temperature management valve is designed to release heated water from the unit during periods of low flow. It comes complete with 12' of 1/4" flexible drain line.

Flow Restrictors
Sterilight UV flow restrictorsThe Sterilight Cobalt Plus Series can be equipped with a flow restrictor to ensure that you do not exceed the maximum flow capacity of the system. We recommend that you choose a flow restrictor rated for slightly less flow than the UV sterilizer based on a UV dose of 40,000 μWs/cm2. For more details, review our flow restrictors page.