Best R.O. System for Reef

detane

Member
???
My whirlpool R.O. system is getting old and replacing the cartridges equals the same amount as just buying a new one. Does anybody which R.O. system would th best for a reef system?
Thanks in Advance!!
 

joncat24

Active Member
I personally think the bfs 161 from buckeye field supply is the best for the money, with what it comes with.
 

jackri

Active Member
Best for a reef I'd definately go RO/DI -- I got the dual reef keeper from airwaterice --- but really any RO/DI 5 stage would work just as well.
Reef though -- go RO/DI.
 

ophiura

Active Member
Yep, many are created equal...because the membranes are basically equal. You do want an RO/DI. The volume depends on your tank size. So if you have a 30g tank, getting a 75gpd RO/DI is a bit of overkill :)
 

aquaguy24

Active Member
Does the gpd rate really matter. Is the water better filtered cuz it's mvng through the filters slower. Just something I've always wondered. Anyone ever did a test with a TDS meter. I have a coralife 4 stage 50gpd unit that I'm very happy with. $155 shipped.
 

aquaknight

Active Member
Originally Posted by aquaguy24
http:///forum/post/3096124
Does the gpd rate really matter. Is the water better filtered cuz it's mvng through the filters slower. Just something I've always wondered. Anyone ever did a test with a TDS meter. I have a coralife 4 stage 50gpd unit that I'm very happy with. $155 shipped.
Technically yes it does matter/there's a difference. The slower the gpd, the higher the rejection rate on the RO membrane is. Meaning more waste goes down the drain, and less, but cleaner water enters the DI stage, causing the DI resin to last a longer time. Something along the lines of a 150gpd unit may have a TDS reading of 30 coming out of the RO, while a 50gpd or so may have TDS in the low teens or single digits, using the same feed water.
Agreed that most already built units are the same, just with different labels. The only thing is get a unit with at least a 10" vertical DI chamber. The cheaper units with the sideways DI cartridge mounted on top of the unit are cheap and ineffective. You can't pack DI resin tight enough for horizontal use.
Some other important things to know is your local water supply. If you chlorine or more probable, chloramine. It's very important to the RO membrane to hav a chloramine carbon block as one of the prefilters (usually the last). Doing so will greatly extend the life of the RO membrane. It's also important to know the micron ratings of your sediment prefilter (the first one). The small the bigger, but life will be shorter. I suggest going with a 1 micron. If you want to use a .5 micron, use it in the 2nd prefilter spot, and use either a 1 or 5 micron filter in the first prefilter slot.
 

florida joe

Well-Known Member
Something along the lines of a 150gpd unit may have a TDS reading of 30 coming out of the RO, while a 50gpd or so may have TDS in the low teens or single digits, using the same feed water.
I have to respectfully disagree your RO/DI unit should be rated for a removal percentage of 97 to 99 present of your influent water no mater what the GPD is
 

cdposey26

Member
Originally Posted by florida joe
http:///forum/post/3096360
I have to respectfully disagree your RO/DI unit should be rated for a removal percentage of 97 to 99 present of your influent water no mater what the GPD is
I agree with you as well. Look at what the membrane is rated for. Most 75gpd that I have seen are rated at 98% removal, the 100gpd I have seen are alot of times 90% removal, but my 150gpd is 98%. After the DI chamber they all should end up the same anyway which should be 0-1 TDS. However the you will use your DI up faster if you have a lower rated membrane.
 

aquaknight

Active Member

Originally Posted by florida joe
http:///forum/post/3096360
I have to respectfully disagree your RO/DI unit should be rated for a removal percentage of 97 to 99 present of your influent water no mater what the GPD is
I stand semi-corrected. A 150gpd unit was a poor example. They have larger RO membranes that typically get 98% rejection. I foolishly assumed they were like 100gpd, but worse.
However 99% of 100gpd units (Dow Filmtec 100gpd RO membrane) have only a 90% rejection rate. Figuring TDS input water of 300, 90% gives you 30 TDS out, while a 75gpd with 98% gives 6 TDS.
Or do you mean after the DI stage? I am just talking about after the RO membrane, before DI. After DI any
TDS readings should be 0-1, which is 100% or 99.99_%
 

florida joe

Well-Known Member
Sorry I am once again going to disagree I do not know of any of the major manufacturers of RO units for the marine hobbyist that remove only 90 present of DTS If you are using a unit with a CTA - Cellulose Tri-Acetate membranes they are in fact in the 88 to 94 range but most if not all of the units we use contain either of the following
TFC - Thin Film Composite membranes which are synthetic and remove between 94-98%.
High Removal Membranes are synthetic membranes with much higher removal rates, between 97.5-99%, and are especially adept at removing silicates.
 

cdposey26

Member
Originally Posted by florida joe
http:///forum/post/3096478
Sorry I am once again going to disagree I do not know of any of the major manufacturers of RO units for the marine hobbyist that remove only 90 present of DTS
Check them closer and I think you will find that almost every 100gpd units on the market the membrane removes only 90% of TDS
 

aquaknight

Active Member
Originally Posted by florida joe
http:///forum/post/3096478
Sorry I am once again going to disagree I do not know of any of the major manufacturers of RO units for the marine hobbyist that remove only 90 present of DTS If you are using a unit with a CTA - Cellulose Tri-Acetate membranes they are in fact in the 88 to 94 range but most if not all of the units we use contain either of the following
TFC - Thin Film Composite membranes which are synthetic and remove between 94-98%.
High Removal Membranes are synthetic membranes with much higher removal rates, between 97.5-99%, and are especially adept at removing silicates.
Pretty much any manufacture for 100gpd units will use a Dow Filmtec RO membrane. I believe some of the China made e-bay ones use a GE membrane, but any of the US guys, thefilterguys, airwaterice, ************** all use Dow Filmtec.
Here is the link to Dow's website with 90% rejection rating.
http://www.dow.com/liquidseps/prod/tw30_1812100.htm
 

florida joe

Well-Known Member
Originally Posted by cdposey26
http:///forum/post/3096491
Check them closer and I think you will find that almost every 100gpd units on the market the membrane removes only 90% of TDS
I have been looking with not luck can you post a link or give me the name of these units
 

florida joe

Well-Known Member
Originally Posted by AquaKnight
http:///forum/post/3096493
Pretty much any manufacture for 100gpd units will use a Dow Filmtec RO membrane. I believe some of the China made e-bay ones use a GE membrane, but any of the US guys, thefilterguys, airwaterice, ************** all use Dow Filmtec.
Here is the link to Dow's website with 90% rejection rating.
http://www.dow.com/liquidseps/prod/tw30_1812100.htm
In all honesty the units I know of in the hobby that produce 100gpd units Pinnacle,Spectrapure,Vertex, Kent and Coralife all deliver over a 95 percent rejection rate.
 

florida joe

Well-Known Member
Originally Posted by cdposey26
http:///forum/post/3096518
start with air water and ice, I know all their 100gpd units are 90%
We are now talking about reef units as per the ops question, I went to the site you suggested and could not find any 100gpd unties with a listed rejection rate can you give me the model
 

florida joe

Well-Known Member
Pretty much any manufacture for 100gpd units will use a Dow Filmtec RO membrane
FilmTec (TFC) membranes are not just a DOW material but an actual Dow Product. Dow owns FilmTec. TFC means thin film composite which give you a 94 to 98 % rejection rate
 

cdposey26

Member
all the reef models, all the 100gpd units are 90% I am sorry if you dont find it, it is what it is. I do not suggest a 100gpd unit because of this.
 
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