View Full Version : Replacement Filters

04/22/2014, 01:17 PM
Hi Russ,

What do you recommend in terms of micron sizes for a 4-stage RO/DI unit (sediment-carbon-RO membrane-DI)?
I've always used 1 micron sediment and .06 micron carbon but recently I read on another vendors site that it should be 5 micron for sediment and 1 micron for carbon. They mentioned that using my original configuration severely restricts the water pressure and decreases my water production.
What are your thoughts on this?

TIA :)

Buckeye Hydro
04/23/2014, 03:19 PM
Assuming you are on city water with no issue with heavy sediment loads, and no chloramines:
1 mic sed
0.5 mic carbon block

I understand the concept the other vendor was getting at, but they should probably do some homework before they advise customers.
For discussion, assume you have a 100 gpd system running at a 4 to 1.
Feedwater flow would be 500 gpd, or 0.3 gpm. At that flow:
Pressure loss w/ 5 mic sediment filter=~0.1 PSI
Pressure loss w/ 1 mic sediment filter=~0.2 PSI

Its a non issue.
If either of the sediment filters clog, then that's a different issue.


05/17/2014, 07:47 AM
Thanks Russ :beer:

Buckeye Hydro
05/17/2014, 08:16 AM
The other rule to follow is that the carbon block(s) pored should be about the same size or LARGER than the sediment filter pore size.