Passive Single-Tank Aeration Systems for Treatment of Iron and Hydrogen Sulfide

Top quality single-tank aeration/filtration units made with heavy-duty standard industry parts for the reduction of up to 8 parts per million hydrogen sulfide and 7 parts per million iron.

A Superb Made-In-USA Product from the Nelsen Corporation, the nation's top builder of backwashing filters.

Sold and Supported by Pure Water Products, LLC.




This Passive Aeration unit is the result of years of experience in the building of single-tank aeration/filtration treatments for iron and hydrogen sulfide. It features the most reliable filter valve made, the tough and proven Fleck 2510, coupled with the latest in SXT electronic technology. The media are the old standards--Birm, Centaur Catalytic Carbon, KDF85, Garnet and Sand.

The Passive Aeration unit comes in two versions: one that is specific for iron, the other for sulfide (rotten egg odor). The iron version can treat up to seven ppm iron and up to 4 ppm sulfide. The version that is designed for sulfide treatment is recommended for up to 8 ppm sulfide but will also handle up to 2 ppm iron.

Passive Aeration works by drawing air into the treatment tank during the backwash/rinse phase during its every-third-night regeneration. The air renews the filter media and remains as a pocket in the upper part of the tank to oxidize ferrous iron to ferric (filterable) iron and hydrogen sulfide to filterable elemental sulfur. The water to be treated enters the top of the tank and is oxidized as it moves through the air pocket. Then the oxidized contaminant is removed by the specialized filter media that fill the bottom 2/3 of the tank. At night, when no water is in demand, the unit backwashes automatically, removing the trapped contaminants, resettling the filter bed, and renewing the air pocket. The backwash frequency and the length of backwash are preset, so the unit comes ready to plug in and use, but the SXT control valve is easily reprogrammed for extreme situations.

This passive aeration treatment system relies on tough, standard industry components and media (Birm, Centaur catalytic carbon, KDF, and more). The control mechanism is a specially equipped Fleck 2510 SXT control valve, the toughest filter and softener valve in existence, that has been modified to draw air rather than brine during its regeneration phase.

The system is pre-programmed and ready to use. It includes everything needed for installation, including drain tubing and a metal bypass valve.

All units use the same underbedding media pack that contains filter sand, garnet, and KDF85. In addition, the iron version contains Birm and the sulfide version has mainly Catalytic Carbon (Centaur) but also some Birm. The media mix gives the unit great versatility.

The unit comes complete with everything you need to install. A metal bypass valve is included as is drain tubing. The 2510 control is pre-programmed, so all you need to do is plug it in and use it. "Assembly" consists of pouring the filter media into the tank (funnel is included) and screwing on the 2510 control.

Like most iron and sulfide systems, the Passive Aeration system has pH requirements (see below), so pre-treatment to raise pH may be required in some cases.

2510 SXT
This passive aeration treatment system comes with the Fleck 2510 SXT controller. The valve oversees the backwash of the filter that renews and resettles the media bed and renews the air pocket in the top of the treatment tank. The attractive and protective environmental cover is standard equipment.


Models Available

Part Number

Iron Treatment Systems


(Free Shipping)

BW751 Passive Aeration Treatement System for Iron in 10" X 54" Mineral Tank $832
BW752 Passive Aeration Treatement System for Iron in 12" X 52" Mineral Tank $917
BW753 Passive Aeration Treatement System for Iron in 13" X 54" Mineral Tank $965

Odor (Hydrogen Sulfide) Treatment Systems


Passive Aeration Treatement System for Hydrogen Sulfide in 10" X 54" Mineral Tank

BW755 Passive Aeration Treatement System for Hydrogen Sulfide in 12" X 52" Mineral Tank $1041
BW756 Passive Aeration Treatement System for Hydrogen Sulfide in 13" X 54" Mineral Tank $1141


Conditions for Operation and Media Content

Part Number Minimum pH Recommended Maximum Service Flow GPM Minimum Backwash GPM Ferrous Iron Treated--PPM Hydrogen Sulfide Treated--PPM Media
BW751 6.8 8 5 7 4

Garnet, Sand, KDF Underbed.

1.25 Cu. Ft. Birm

BW752 6.8 11.5 7 7 4

Garnet, Sand, KDF Underbed.

1.75 Cu. Ft. Birm

BW753 6.8 13 7 7 4

Garnet, Sand, KDF Underbed.(double portion).

2.00 Cu. Ft. Birm



BW754 6.8 8 5 2 8

Garnet, Sand, KDF Underbed.

0.5 Cu. Ft. Birm

0.75 Cu. Ft. Centaur Carbon

BW755 6.8 11.5 7 2 8

Garnet, Sand, KDF Underbed.

0.75 Cu. Ft. Birm

1.00 Cu. Ft. Centaur Carbon

BW756 6.8 13 7 2 8

Garnet, Sand, KDF Underbed (double portion)

0.75 Cu. Ft. Birm

1.25 Cu. Ft. Centaur Carbon

We stock all parts for the Passive Aeration units.

This equipment is not yet linked to our shopping cart, but you can order by calling 940 382 3814.

Prices on this page include shipping.

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940 382 3814

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