when to replace ro filter

[reefinmike]

my tds recently shot up from 1 to 18 in two weeks so i figure it is time to change some filters. i have had the unit for almost a year. i read somewhere that the actual ro membrane doesnt need replaced as often, do i need to change the pre-filters and DI or all of it??

thanks

mike

 

[bljohnson]

Yes - those need to be replaced more frequently.

Try going to these sites for more info:

airwaterice.com
buckeyefieldsupply.com
thefilterguyz.biz

I have never used any of these vendors but if you do a search on RC they only have very positive reviews.

 

[TacoKing]

Buckeyfieldsupply.com is great.

Before you swap out your RO membrane just switch the DI, carbon and sediment filters. RO shouldn't need replaced for a long time.

-Rob

 

[bljohnson]

I'm sorry - I just relalized my answer was kind of vague. I agree with Tacoking. Also do a search on flush kits to prolong the life of your RO (which is the most expensive membrane). Also alot of members use refillable DI kits which are pretty cheap compared to prefilled ones.

 

[reefinmike]

mk

mk

ok, that is what i thought. i do have a flush kit on my unit now and i flush it for about half an hour every month or so.

 

[AZDesertRat]

To answer your question. Prefilters and carbon filters need to be changed every 6 months like clockwork. DI needs to be changed when you begin to see a consistent rise in finishedwater TDS. If you normally see 0 TDS after DI, which you should with a quality RO/DI, change resin when you see about 3 all the time.
Prefilters and carbons have very little effect if any on finshed water TDS as they are there to protect the RO membrane which does 98% of the work. Prefilters are designed to trap suspended particles (sand, grit, etc.) larger than their rated micron size. Carbons are designed to adsorb chlorine and volatile chemicals so neither really has any effect on dissolved solids which are microscopic in comparison, thats where the membrane comes in and the DI that does the final polishing.
Remember to replace them every 6 months regardless of water produced so you lessen the chance of bacteria growth inside the housings. Also disinfect the housings as recommended to further lessen the chance of contamination.

 

[TimFountain]

<a href=showthread.php?s=&postid=7439566#post7439566 target=_blank>Originally posted</a> by AZDesertRat
To answer your question. Prefilters and carbon filters need to be changed every 6 months like clockwork. DI needs to be changed when you begin to see a consistent rise in finishedwater TDS. If you normally see 0 TDS after DI, which you should with a quality RO/DI, change resin when you see about 3 all the time.
Prefilters and carbons have very little effect if any on finshed water TDS as they are there to protect the RO membrane which does 98% of the work. Prefilters are designed to trap suspended particles (sand, grit, etc.) larger than their rated micron size. Carbons are designed to adsorb chlorine and volatile chemicals so neither really has any effect on dissolved solids which are microscopic in comparison, thats where the membrane comes in and the DI that does the final polishing.
Remember to replace them every 6 months regardless of water produced so you lessen the chance of bacteria growth inside the housings. Also disinfect the housings as recommended to further lessen the chance of contamination.

Great summary. I found an inline TDS meter on ebay for $35 that really helps to track this.