Q. Why are these systems called "Catalox" filters.

A. Catalox is a trademarked name. These iron filters use a type of granular filter media called "Catalox". These are similar to Filox and Pyrolox, in that the media is a pure granular manganese oxide naturally produced from manganese ore.


Q. How do they work?

A. As the water flows through the filter tank containing Catalox media, a reaction occurs where the dissolved ferrous iron compounds form an insoluble ferric hydroxide. In plain English, as water containing iron flows through the media, the Catalox causes the iron (and manganese and hydrogen sulfide) to form rust, or solid iron, manganese and sulfide particles. After these rust particles get trapped in the filter media, once or twice a week they are automatically backwashed out to drain, and the filter media is ready to filter again.


Q. Why does it need to backwash?
A. A periodic backwash flushes out the trapped iron and manganese that the iron filter removes, restoring the flow rate and pressure and keeping the Catalox media clean.


Q. What is the difference between "greensand iron filters" and Catalox iron filters?

A. The difference between Greensand iron filters and Catalox filters is the type of media used. Catalox filters use Catalox (similar to Filox and Pyrolox meda). Greensand is a lighter media, created by coating silica with a manganese oxide coating. It needs to be regenerated with potassium permanganate, or use with chlorinated water, where chlorine bleach is fed in upstream of the filter. Catalox is actually pure manganese oxide, it is not a coating. It is much heavier, requires a much higher backwash flow rate. Catalox can work in some applications where the iron levels are less than 5.0 ppm and there is no sulfur odor present and last for years with just simple backwashing. In these applications, no chlorine feed is required. However for many waters with hydrogen suflide present, or higher levels of iron, and/or manganese, a chlorine feed is recommended ahead of the Catalox filter. To ensure longer life, we do recommend a chlorine feed ahead of the Catalox filter.


Q. How often do these iron filters need to backwash?

A. Once every 3 to 4 days is usually sufficient, although you can set it to backwash every 1 or 2 nights if the iron is very high and there is a lot water used in the home. The backwash lasts for about 8 minutes and the it rinses for 6 minutes. The backwash control is fully automatic and is typically set to backwash in the middle of the night.


Q. Can I order the Catalox filter so it backwashes based on flow and not days of the week?

A. Yes you can. The Fleck 7000 model can be ordered with an optional flow sensor, when you check out you are able to check this option ($49 additional). This not only allows the neutralizer to backwash based on gallons used, but it allows you to see the flow rate in gallons per minute of the water used in the house.


Q. Do these systems come in different sizes?

A. Yes. The size of the filter system is directly proportional to the flow rate of the water, in gallons per minute. The higher the flow rate, the larger the system required. See our table for the flow rates for Catalox iron filters.


Q. Do these filters have any special conditions to work properly?

A. Yes! The minimum backwash flow rate is necessary to be able to properly backwash and restore the Catalox media. The water should have a pH of 6.0 to 9.0. For water containing over 3.0 ppm of iron, or water containing hydrogen sulfide gas ('rotten-egg' odor) chlorine (or ozone or hydrogen peroxide or air) injection is recommended 10 to 30 seconds upstream of the filter. Catalox media works best if the water is pre-chlorinated, but it can be used without chlorination if the iron is less than 3.0 ppm and it is backwashed frequently.


Q. My water is hard also, I am thinking of using a water softener with an iron filter. Is that a good approach to consider?

A. Absolutely. Many people use a Catalox iron filter first in line, followed by a good quality water softener. The Catalox filter will remove iron, and the softener will remove the hardness.


Q. My water has a very bad smell of sulfur ("rotten-eggs"), is this a problem?

A. We recommend a chlorinator and/or an air-compressor-tank be installed prior to the Catalox filter to enhance the odor-removing capabilities of the Catalox filter. If hydrogen sulfide (the rotten-egg odor you are smelling) is present, the media will only remove very low levels without a chlorine feed ahead of the Catalox filter. For water with odor and/or iron bacteria, the media works better and lasts years longer if you install a simple chlorine feed pump ahead of the iron filter. In some wells, if odor is present, there may also be iron bacteria and/or sulfur bacteria present. The Catalox iron filter will not kill this bacteria, so the bacteria can still cause odors after the filter, in the household plumbing, particularly if the water sits for a period of time. What happens is, the Catalox filter will remove it, but if there is any residual iron in the pipes, any pipes made of iron, the odor can come back after the pipes have sat unused for a day or two.


Q. My water has a weak-tea color, or is brown in color. The color does not settle out very much in a glass, even after I let it sit for a day or two. Will Catalox work for this type of problem?

A. Probably not, you may need to use the Catalox filter and add a Tannin filter after the Catalox filter for color removal.


Q. Are these systems big electrical power users?

A. No. The control valve uses only about 15 watts of energy to run the timer and backwash valve.


Q. What maintenance is required?

A. Under the right conditions there is littleor no maintenance. This is the great advantage of the Catalox filters. Catalox can last for over 10 years with little maintenance. In some cases depending on how hard the water is, the control valve backwash piston needs to be replaced every 3 to 5 years, but this is also easy to do by anyone. No special tools are required. The systems uses no salt or chemicals and there are no filter cartridges to replace.


Q. Is there a pressure loss through the system?

A. When properly sized, the system produces a very low pressure drop at service flow rates, usually around 5 psi.


Q. Can I route the backwash water to my septic tank?

A. Yes. The backwash water is non toxic and can be routed to the septic tank with no problem. It can also be routed to landscaping, although the backwash is usually very dark and orange, and will stain surfaces.


Q. How frequently do I have to replace the filter media?

A. The filter media will last for 5 - 15 years depending on usage and conditions. It is easily replaced.


Q. How much does it cost to change the Catalox media?

A. It costs around $400 to change the Catalox media for a typical 1.5 cubic foot size Catalox filter.


Q. Can I get assistance in choosing an iron filter system for my application?

A. Yes! You should first have your water tested, and then contact our technical staff for help on selecting the best iron filter system for your application. Also see our Custom Water System Design Questionnaire which makes it easy to help you select a system.