Monday, November 25, 2013

Using Alum and MangOX to Remove Turbidity


I have turbidity in my well water. I saw one of your articles using Alum injector and a mangox filter. Is this a good solution? Test from the well driller was 1.85 for turbidity.

Dan K.

Hello Dan,

Yes, an alum injector and MangOX filter will remove turbidity from your water very well, though we recommend using a sediment backwash filter instead, unless your water also contains iron and manganese.  

As you may have read in our article, alum injection is the most popular method for treating turbidity, used not only by homeowners but by many municipal treatment centers as well.  When introduced to turbid water, alum causes the organic matter and colloidal solids that cause turbidity to flocculate (clump together to form a larger mass) and become more easily filterable.  We recommend using a contact tank after the alum is injected to ensure that it is thoroughly mixed in the water, and to aid in flocculation, which is stimulated by mild agitation.  

After that, you could use a MangOX filter, though a Chemsorb Sediment Backwash Filter will be just as effective at removing the flocculated turbidity particles.  See the diagrams below for an illustration of how these systems might be installed:

A sediment backwash filter installation (click to enlarge)
A MangOX filter installation (click to enlarge)

Some people choose to use both a sediment backwash filter and MangOX filter to remove turbidity - if you choose to use both systems be sure to install the sediment backwash filter before the iron filter.

You can also treat cloudy water without injecting any chemicals with a reverse osmosis or ultra-filtration system, or by using a cartridge filter before your sediment backwash filter, though this latter option is not quite as effective as the others mentioned here.  Also note that both ultra-filtration and reverse osmosis systems will require a pre-filter to preserve the integrity of their UF/RO membranes - consider an alum injector and sediment backwash filter followed by a UF or RO system for maximum effectiveness.

Thanks for the letter, Dan.  We hope you'll let us know how your treatment goes.  If you follow these guidelines we're sure you'll see that cloudy water turn clear in no time.  And don't hesitate to send any further questions or comments to or our Facebook page.  Thanks!