Additional RO filter

Hi all,

I have a standard 5 filter RO under the sink, but have a huge filter vertically next to it. Much bigger than the others. What kind of filter is it?

Thanks!

 

Most packaged RO systems include equally sized 10" X 2.5" filters. Assuming that larger filter is feeding the RO unit (as opposed to feeding the regular kitchen faucet), I suspect it will contain a carbon cartridge for removal of chlorine or chlorimine, either of which is common in municipal sourced water.

As it seems you did not have this RO unit installed, the filter's contents cannot be assured until the housing sump is removed so as to expose the cartridge inside.

 

ah! It looks like this:

 

Appears to be carbon of some type but, can't see the sides clearly. Any markings or numbers on sides or bottom of the cartridge? Where is that filter connected to?

If the unit was already in the house when you moved in, you probably don't know when the cartridges and the RO membrane were last replaced. Suggest replacing them all and sanitizing the housings and storage tank while the housings are empty.

The effectiveness of the membrane can be tested against the raw water using an inexpensive TDS meter, but membranes are relatively inexpensive and so replacing it with the cartridges may give you peace of mind that everything is clean, renewed and working as well as intended for your family initially.

The membrane will typically need replacing every 2-4 years whereas filter cartridges, 6-12 months.

 

Hard to say, it could be a remineralizer of some type, an alkaline filter, specialty contaminant filter (bone char for fluoride reduction, etc...) or even a Di filter.