RO/DI replacement filters

bad santa

SCRK member
I want to replace all the filters and my 5 stage ro/di unit. I know i can get them from bulkys and filterdirect but i was wondering if any of you guys have ordered the filters from ebay. I want to replace the membrane filter so should i stay with the GE 100 gpd or should i go with onother one(75 or 50)?
 

golfish

Team RC
Re: RO/DI replacement filters

<a href=showthread.php?s=&postid=14187049#post14187049 target=_blank>Originally posted</a> by bad santa
I want to replace all the filters and my 5 stage ro/di unit. I know i can get them from bulkys and filterdirect but i was wondering if any of you guys have ordered the filters from ebay. I want to replace the membrane filter so should i stay with the GE 100 gpd or should i go with onother one(75 or 50)?

Ed, You probably know why you should stay away from the 100 gpd membrane so I wont go there. If you want the best go with Spectrapure on your membrane... The other carts you can get from filterdirect.

Don't go cheap here man...its not worth it.
 

speargunhunter

New member
try "isopurewater" in santa ana is a small company i add a DI to my 4 stage system for 24 bucks they have good prices i have the number if you want..
 

bad santa

SCRK member
Re: Re: RO/DI replacement filters

Re: Re: RO/DI replacement filters

<a href=showthread.php?s=&postid=14187165#post14187165 target=_blank>Originally posted</a> by golfish
Ed, You probably know why you should stay away from the 100 gpd membrane so I wont go there.

Don't go cheap here man...its not worth it.

I should know and i know i have read it in the past but i dont remember at the moment. I read alot about the ro/di units a few years ago but i just got a good deal on a used unit and i want to replace the filters.

Can you give me the condensed version of why i should stay away from the 100gpd membrane.

On a side note, thanks for the drum. I am using that for my ro/di water.
 

bad santa

SCRK member
Which micron should i be looking at for the carbon blocks? I dont quite know about the different micron ratings. Does anybody have a link to a filter discussion here on RC?
 

reef_doug

Premium Member
For a 5 stage, I would run it like this:

1 micron sediment
.5 or .6 Matrikx+1 chlorine guzzler or PB+1 if you have lead pipes
2 DI (reefgeek is ok on price but cheaper is the refillable cartridges). Swap out one cartridge every 3 months and move the oldest to the 4th position and newest one at the end.
 

cthetoy

Active member
Re: Re: Re: RO/DI replacement filters

Re: Re: Re: RO/DI replacement filters

<a href=showthread.php?s=&postid=14187299#post14187299 target=_blank>Originally posted</a> by bad santa

Can you give me the condensed version of why i should stay away from the 100gpd membrane.water.

The 75 gpd membrane will save you money on the DI resin which costs the most to replace

The major difference is in the rejection rate and the life of your DI cartridge. All of our reefkeeping systems are designed to make -0- tds water. The 75 gallon per day membrane is rated to reject about 98% of the TDS. The 100 GPD Membranes is rated at about 90%. That difference changes the amount of work the DI has to do. The non rejected TDS is mopped up by the DI so the less mopping up to do, the longer the DI lasts. A DI cartridge is rated at 6,800 PPM Divide the 6,800 by the output of the membrane to guesstimate the number of gallons you can expect from the DI.
Example: Tap water 200PPM. The expected output of the 75 gpd would be 6-12 ppm. The expected output of the 100 gpm would be 20-40 ppm. Actual values are dependent on you tap water quality, pressure and temperature. 6800 > 12 = 566 gallons 6800 > 40 = 170 gallons.
 

golfish

Team RC
Ed,
Pretty much what cthetoy said.....other then that I like to run two DI carts just to make sure I polish out all the PO4's.....
 
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