RO/DI filter replacement?

[Bobby417919]

It is time for me to replace the filters in my RO/DI. It is a five stage filter, the filters I am most concerned with are the first 3 filters. I have done some research and I have came up with 2 possible set ups.

Set Up 1 - The first filter is 1 Micron Sediment, the second is a .5 Micron Sediment, and the third is a .5 Carbon then a RO membrane, and last is a DI.

OR

Set Up 2 â€"œ The first filter is a 1 Micron Sediment, the second is a 1 micron Carbon, and the third is a .5 Carbon then a RO membrane, and last is a DI.

Which one would you pick?

Any other set ups are welcome.

Thanks,
Bobby

 

[snulma1]

I know mine is dual stage carbon filtration. But take a look at your incoming water, do you need dual sediment filters?

 

[Bobby417919]

I have a duel TDS meter and its reads 75-85 coming in and 3 going out (it use to be 0).

With the reading above do you think I need a dual sediment filters?

 

[DarG]

I think the dual carbon is more common because the water will have to go through two carbon stages giving carbon a better chance to get out some of the chemicals/substances that it is good at removing. My setup uses a 5 micron sediment - 5 micron carbon and then a .6 micron carbon then on to the RO and then DI. I think that this or something similiar is most common. I have a TDS of about 150 ppm from the supply water, 3 ppm after the RO and 0 after DI.

Couple people here with more filtration experience that may have more/better to add.

 

[HowardW]

<a href=showthread.php?s=&postid=9921324#post9921324 target=_blank>Originally posted</a> by Bobby417919
I have a duel TDS meter and its reads 75-85 coming in and 3 going out (it use to be 0).

With the reading above do you think I need a dual sediment filters?

If your TDS went from 0 to 3, that has nothing to do with the sediment and carbon filters, that means your DI media needs replacement. I also see no reason to run 2 sediment filters.

 

[AZDesertRat]

A single prefilter andasingle carbon block should be sufficient if they are the proper micron ratings. I use either a 0.5 micron or now a 0.2 micron prefilter and a 0.5 micron Chlorine Guzzler carbon block. The 0.2 micron prefilter is a pleated filter and has 10x the surface area of a normal poly prefilter as is absoute rated instead of nominal rated, which means it is much more effective. The 0.5 micron carbon block is good for 20,000 gallons of normally chlorinated water where a 1 micron size might do 9,000 gallons, a 5 micron 3,000 gallons and a 10 micron maybe 1,500 gallons tops. Its worth it to go with the best. You have to remember all water entering the unit passes through the pre and carbon including the 4:1 waste stream not just the final product water so you want good filter capacity.
I might would look at a 0.5 pre, 0.5 carbon, RO, DI and convert the empty housing to a second DI for the best quality water.

And yes, the rise in the final TDS has nothing to do with the pre and carbons, its the membrane or the DI that is in need of attention and probably the DI if you have taken care of the RO and its no more than a year or two old. Membranes normally last 2-3 years if you use good filters and disinfect the housings with filter changes and longer if you use high quality filters like the 0.5 micron sizes. 9-10 years is not unheard of with units like Spectrapure that use high quality filters.