RO unit question

goodymj · 05/15/2007, 10:48 AM

I'm going to be starting up a 90 gal reef tank in the coming months and I have a question regarding reverse osmosis filters. What's the difference between the standard GE RO I have and the reef-specific ones like the Captive Purity series? How can I test the effectiveness of the unit I have?

Thanks

sanababit · 05/15/2007, 10:54 AM

an r/o is an r/o, no matter what brand. both will work the same, they both have a membrane, the membrane is the one that purifies the water and leaves it a about 0 to 10 ppm, good luck

ps you can get one cheap at home depot

sana

mg426 · 05/15/2007, 11:00 AM

Not really sure what it is you are asking but all of the reef grade units use top of the line filters and membranes. These will really extend the life of your DI resin.

a2fire2i · 05/15/2007, 11:18 AM

http://www.thefilterguys.biz/ro_di_systems.htm

I just got the OCEAN REEF + 1 system and love it.

Aquarist007 · 05/15/2007, 11:25 AM

Quote:

Originally posted by mg426
Not really sure what it is you are asking but all of the reef grade units use top of the line filters and membranes. These will really extend the life of your DI resin.

that's a really good point---I just replaced the other two filters for 15 dollars the other one is 100$--well worth taking care off by regularily changing the other two.
Scott

goodymj · 05/15/2007, 11:35 AM

Quote:

Originally posted by mg426
Not really sure what it is you are asking but all of the reef grade units use top of the line filters and membranes. These will really extend the life of your DI resin.

I have a GE RO filter at home now. I got it at Home Depot (sana) mostly for drinking water. I currently don't have a DI unit. Are the reef RO units better at removing stuff (nitrates, etc.) that you don't want in your aquarium water, or are these units just marketing gimmicks? I know a DI filter would further reduce the particulates and I should get one, but I can't get one just yet. Is my GE unit good enough for now? Would a reef-specific RO/DI unit be worth the $300 considering I already have a decent unit (I think)?

a2fire2i · 05/15/2007, 11:36 AM

You can tell the effectiveness of the RO unit by taking the RO TDS reading, and dividing that by the tap water reading. My RO reading was 9, and the tap reading was 281. 9/281=.032 *100 =3.2%. Now you take that number and subract it from 100%, which gives you your rejection rate. A good unit, should be able to give you 96-98%.

AZDesertRat · 05/15/2007, 12:52 PM

Generally drinking water systems have lower capacity membranes which produce somewhere between 15 and 30 GPD. Most reef quality systems produce 75 GPD or more. With a drinking water system you could wait days to do a top off and weeks to fill a new tank. Membrane production is based on water being 77 degrees F and 50 to 60 psi, if your press or temp are less it will not produce as much. Most people find they get about 2/3 to 3/4 of the rated capacity due to conditions that are not optimal.
Some drinking water systems use membrane that are a little less efficient, in the 90 to 96% rejection rate vs 96 to 99+% for reef quality systems. 2 or 3% does not sound like much difference but a very accurate rule of thumb says for every 2% you increase the RO membrane efficiency you double the life of the DI resin. This can save you a bunch of money in a very short time if you make much water.
Drinking water systems normally have larger micron rated, less efficient prefilters and use granular activated carbon. Good reef systems use low micron rated prefilters for better sediment and particulate filtration and low micron rated solid carbon blocks for excellent chlorine, chloramine and VOC removal for extended periods of time. Granular media in front of a membrane is not recommended as it turns to powder and can clog a membrane. It aslo has a very short lifespan, sometimes measured in the 100s of gallons versus up to 20,000 gallons for a carbon block. The better job you do before themembrane the longer the membrane will last.
You can upgrade all the filters in the unit you have and add a DI chamber but you will be very close to the cost of a good reef quality system in most cases.

goodymj · 05/15/2007, 03:00 PM

Thanks AZDesertRat. That's exactly the info I was looking for. Looks like I'll use the GE unit for drinking water and install a new reef quality system in my utility room.

05/15/2007, 10:48 AM	#1
goodymj Registered Member Join Date: Feb 2007 Location: Maricopa, Arizona Posts: 13	RO unit question I'm going to be starting up a 90 gal reef tank in the coming months and I have a question regarding reverse osmosis filters. What's the difference between the standard GE RO I have and the reef-specific ones like the Captive Purity series? How can I test the effectiveness of the unit I have? Thanks

05/15/2007, 10:54 AM	#2
sanababit Registered Member Join Date: Apr 2007 Location: Uranus Posts: 3,094	an r/o is an r/o, no matter what brand. both will work the same, they both have a membrane, the membrane is the one that purifies the water and leaves it a about 0 to 10 ppm, good luck ps you can get one cheap at home depot sana __________________ Senior Member of the "Hardly any Water Changes, Temp Swinging, T5ing, No Qtining, Frag Exchanging for Fish Food Current Tank Info: 90RR inwall, Octopuss Skimmer, 2 MP40 wQD, 1 MP10 WQD, 2 Radions G4 Pro, Apex Doser, Apex Controller, 400w heater, 30 Gal Sump, Biopellets, Carbon, Gfo, Macroalgae

05/15/2007, 11:00 AM	#3
mg426 Registered Member Join Date: Jan 2006 Location: maryland Posts: 6,923	Not really sure what it is you are asking but all of the reef grade units use top of the line filters and membranes. These will really extend the life of your DI resin. __________________ I found a way to make a small fortune running a reef tank. Start with a large fortune. Unofficial President of the SEACLONE haters club Current Tank Info: 125 mixed reef 110 lbs LR, 1x250watt XM 20K MH 2x175watt XM 20K MH on Magetics 2X96 watt actinic PC, 220 watt VHO actinic, 30 gallon refugium, closed loop system powered by Sequence Dart MSX 200 skimmer 38 gallon sump, Oceansmotions squirt

05/15/2007, 11:18 AM	#4
a2fire2i Premium Member Join Date: Nov 2005 Location: Sarasota, FL Posts: 1,964	http://www.thefilterguys.biz/ro_di_systems.htm I just got the OCEAN REEF + 1 system and love it. __________________ Corey Current Tank Info: 120 Mostly SPS Reef

05/15/2007, 11:36 AM	#7
a2fire2i Premium Member Join Date: Nov 2005 Location: Sarasota, FL Posts: 1,964	You can tell the effectiveness of the RO unit by taking the RO TDS reading, and dividing that by the tap water reading. My RO reading was 9, and the tap reading was 281. 9/281=.032 *100 =3.2%. Now you take that number and subract it from 100%, which gives you your rejection rate. A good unit, should be able to give you 96-98%. __________________ Corey Current Tank Info: 120 Mostly SPS Reef

05/15/2007, 12:52 PM	#8
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Generally drinking water systems have lower capacity membranes which produce somewhere between 15 and 30 GPD. Most reef quality systems produce 75 GPD or more. With a drinking water system you could wait days to do a top off and weeks to fill a new tank. Membrane production is based on water being 77 degrees F and 50 to 60 psi, if your press or temp are less it will not produce as much. Most people find they get about 2/3 to 3/4 of the rated capacity due to conditions that are not optimal. Some drinking water systems use membrane that are a little less efficient, in the 90 to 96% rejection rate vs 96 to 99+% for reef quality systems. 2 or 3% does not sound like much difference but a very accurate rule of thumb says for every 2% you increase the RO membrane efficiency you double the life of the DI resin. This can save you a bunch of money in a very short time if you make much water. Drinking water systems normally have larger micron rated, less efficient prefilters and use granular activated carbon. Good reef systems use low micron rated prefilters for better sediment and particulate filtration and low micron rated solid carbon blocks for excellent chlorine, chloramine and VOC removal for extended periods of time. Granular media in front of a membrane is not recommended as it turns to powder and can clog a membrane. It aslo has a very short lifespan, sometimes measured in the 100s of gallons versus up to 20,000 gallons for a carbon block. The better job you do before themembrane the longer the membrane will last. You can upgrade all the filters in the unit you have and add a DI chamber but you will be very close to the cost of a good reef quality system in most cases.

05/15/2007, 03:00 PM	#9
goodymj Registered Member Join Date: Feb 2007 Location: Maricopa, Arizona Posts: 13	Thanks AZDesertRat. That's exactly the info I was looking for. Looks like I'll use the GE unit for drinking water and install a new reef quality system in my utility room.