tannin

[bdr]

so i am in the country and our well water has tannin. Just out of the tap it looks fine but in volumes you can definaetly see it as yellowed water. will a rodi system clear this up?

 

[UVvis]

It will, but it will eat through your RO/DI system in a hurry.

Put a carbon filter inline first to pull out the tannins before moving forward.

 

[bdr]

it already goes through a sediment filter, carbon filter, water softener, then a componet that is suppossed to remove sulfur and iron not sure what its called though...

so after that just a standard rodi unit? This is one i was looking at at one of the small lfs


http://fortyfathoms.net/index.php?route=product/product&path=52&product_id=278

 

[Randy Holmes-Farley]

Tannins will not get through the RO because they are large molecules relative to an inorganic ion, so while well water may deplete the DI rapidly if it has high TDS, I would not attribute DI depletion to such organic molecules.

here's a typical tannic acid:

 

[bdr]

glad to hear i know the resin isnt cheap but my tank is going to be a 90 dt and 55 sump im sure it will be cheaper and even if its even in price much easier then buying and lugging water for years... someone told me they thought it would take it out but i thought id get a few more and maybe more educated opinions on the subject!

 

[UVvis]

bdr,

After the water goes through your filtration, is it still yellowish in color?

The RO membrane should keep the organics out, but some RO membranes do not last very long with high organic loadings, increasing cleaning and replacement periods, depending on the RO unit being run.

 

[bdr]

i change filters monthly and yeah same color with a new filter as an old filter or no filter but i dont have any rodi unit yet

 

[Boomer]

You may want to look into OFR (Organic Fouling Resins) that are designed to remove Tannin from water. There are quite a few places in Minnesota where people have the same issue as you. A company called Kinetico is such a water softener company that some use in Minnesota but you already have a WS.

There actually are household water tannin filters and resins. The resins often used are ResinTech SBACR-HP Organics and Tannin Resin. These resins can also be regenerated. You could easily DIY your own. The first thing you need to know is what is the Tannin level. There are also test kits, one made by LaMotte, that tests for Tannin and Lignin.

Tannin Resin
http://www.ohiopurewater.com/shop/customer/product.php?productid=173&cat=321&page=1

 

[bdr]

on the scale of the link you gave boomer i would be in the .5-2 range heavier on the 2 would be my guess is this something that goes in a cannister filter? hopefully for 300 its not just a one shot deal