Manufacturer Changes Katalox Light’s Name to Katalyst Light

by Gene Franks

The popular iron/manganese medium that has been sold for a number of years as Katalox Light will in the future be called Katalyst Light. The German manufacturer, WatchWater, has given no explanation for the name change. One would assume a patent violation.

If you buy Katalox and it comes in a bag or box labelled Katalyst, or if you buy Katalyst and you get Katalox, not to worry. Regardless of what the bag says, it’s the same material.

While we’re revising the product name on our website,  we will also be changing the minimum backwash and maximun service flow recommendations for the filters we furnish that use Katalox/Katalyst.  The manufacturer’s original recommendations were, to be blunt, way too good to be true, but we based our recommendations on them.  The newer Katalox/Katalyst brochures have more realistic numbers and we are revising ours accordingly.

A Fool’s Errand

Sizing and setting up a backwashing filter for iron and/or manganese treatment is largely a guessing game. The more that’s known about the water being treated, the more accurate the guess can be, but in the end, it’s still a guess.  There are simply too many factors that influence backwash and service flow requirements for a “one size fits all” sizing chart to work for everyone.

Manufacturers of iron/manganese products like Katalox (Katalyst) and Filox-R pass the sizing decisions on to the user of the product by providing only vague, generalized sizing information.  The new Katalyst literature states the service flow capacity of the medium as 4 to 12 gallons per minute per square foot.  (That is, square feet of surface area of the media bed.  A 10″ diameter tank, for example, has a surface area of 0.54 square feet, while a 13″ tank has an area of about 0.92 square feet,) With Katalyst, therefore, the manufacturer is saying that if you use a 10″ tank you can treat a maximum service flow to your home of up to somewhere between 2 and 6.5 gallons per minute.  The exact service flow capacity for the individual home depends on such factors as whether you are treating iron, manganese, or a combination of the two, if there are other competing contaminants in the water (like hydrogen sulfide), the pH of the water, the oxygen content of the water, and pre-treatment provided.


With backwash rate requirement, the big unknown (to most users) is the water temperature. Cold water backwashes a filter much more efficiently than warm water, so less backwash water is needed if the water is cold. Filox’s manufacturer states the backwash requirement between 16 and 23.5 gpm per square foot, depending on the water temperature–in other words, between 8.5 (cold water) and 12.5 gpm (warm water) for a 10″ filter tank. Other important variables, like the total contaminant content, enter the equation as an educated guess. Obviously, a more vigorous  backwash is required to clean a media bed if the iron content of the treated water is 10 parts per million as opposed to one ppm. The type of tank used also matters. We use Vortech tanks for most filters and assume, based on manufacturer’s data, that Vortech tanks increase backwash efficiency by at least 20%.


With that in mind, here’s how we are revising our Katalyst (Katalox) recommendations.  The numbers are simply a guess based on the average of the high and low figures given by the manufacturer.  For example, Katalyst recommends a minimum backwash rate of  10 to 12 gpm/ft2, so we used 11 gpm/ft2.


Tank Diameter in Inches Maximum Service Flow–GPM Minimum Backwash Rate — GPM – With Vortech Mineral Tank Minimum Backwash Rate — GPM – With Standard Mineral Tank
9 4 4 5
10 5 5 6
12 6 7 9
13 7 8 10

Charts like this are not a guarantee of performance. They should be used as a starting place. If your contaminant content is high, decrease the maximum service flow accordingly. If you are planning a filtration project, we can’t guarantee a perfect outcome, but we can help you make an educated guess at sizing. The more information you can provide about the water, the better the chance of a good outcome.