I have ? about RO/DI systems

lakwriter · 03/13/2007, 06:44 PM

I am considering purchasing an RO/DI system, but I need some help understanding how they are used & installed. I currently use RO water from my LFS.

Questions...
1. Are RO/DIs permemantly plumbed in, or can they be connected and disconnected from, say, a laundry tub spigot?

2. Do they come in small capacities, like 5 gallons per day? I don't need a lot of water and I would like to hook up 24 hours before its needed to produce my change water. I don't have room to store many gallons of water.

3. What added value do you get from RO/DI as opposed to just RO?

Thanks!

mg426 · 03/13/2007, 06:57 PM

RO/DI systems can be very portable. I believe that the best membrane is a 75 gallon/day DOW filmtec. the DI stage removes the remining impurities that the RO cant remove. AZdesertRat will most likely jump in here and answer anything you need to know.

lakwriter · 03/13/2007, 07:10 PM

Is it reasonable to hook up the system for a few hours to make the amount of water I want and then disconnect? I can set it up so I can watch it and make sure it doesn't overflow.

AZDesertRat · 03/13/2007, 07:25 PM

Membranes generally come in 25, 50 and 75 gallon per day varieties. There are others such as 100 GPD which in some cases is not a real RO membrane but is a nanofilter which is one step below RO and not as efficient. Others include Spectrapures 90 GPD which is similar to a 75 and their new 150 GPD which is the best thing since sliced bread.

The biggest advantage of the 75 GPD and up is it makes water much faster than a 25 or 50 GPD, 50% to 300% faster so you don't stand around watching it drip....drip...drip. The cost and the physical size is basically the same between all of them so get the 75. Remember with the smaller on it takes 24 hours to make that quantity and that under perfect conditions which are 77 degree water temperature and 50 to 60 psi incoming pressure which is not always the case. Lower temps and/or pressures affect output and it can cut it 50% or more easily.

They can easily be screwed onto a kitchen faucet or a hose bib type connection either outside or next to the washing machine. Waste flows can be reused in a washing machine, in the garden, lawn, pool or any number of good uses. I mounted mine over my laundry sink in the garage so if I forget to shut it off and it overflows it goes into the sink and not on the wifes kitchen floor.....not that I have ever done that before

.

Colin · 03/14/2007, 08:58 AM

You can use one of those garden hose "Y" adapters to hook it into the spigot that feeds your washing machine. That way you don't have to continually connect and disconnect your washer. You can also just set the bucket on the washer lid, so that if you do forget, it will just go into the washer tub (I do this all the time). The water will overflow the bucket and go into the crack around the washer lid.

Don't bother with anything but a 75G/day. Anything less is a rip-off, and the 100's don't work as well (as mentioned above). The exception is the Spectrapure units like the 90 (which is really a 75), but they seem to make thier own marketing rules when it comes to GPD.

--Colin

Pyrrhus · 03/14/2007, 09:39 AM

Actually Spectrapure uses industry standard parameters when stating the production of the membranes that they sell.

When Dow released the Filmtec membranes they chose to rate them at 50 psi rather than the industry standard of 60 psi. If you rate a Filmtec at the industry standard of 60 psi the GPD rating is significantly higher than the manufacturers stated capacity.

Colin · 03/14/2007, 09:59 AM

That's true, but it's still a marketing trick. That would apply to any Dow Filmtec membrane. If you're buying Spectrapure just because it's advertised as 90 gal/day instead of 75 gal/day, then you've been had.

At any rate, they're still good products. That's reason enough to buy from them.

--Colin

AZDesertRat · 03/14/2007, 12:56 PM

You buy Spectrapure to get their SpectraSelect individually hand tested and guaranteed 98+% rejection rate RO membranes. No one else offers this individualized service or performance guarantee, no one. Mine is running at over 99% rejection, anywhere between 99.19 and 99.25% to be exact.

Pyrrhus · 03/14/2007, 04:02 PM

The marketing gimmick is actually on the part of Dow, not Spectrapure.

lakwriter · 03/14/2007, 04:46 PM

Is Spectrapure one of the better brands? What are some other good brands?

landfish · 03/14/2007, 05:23 PM

I have only seen a few brands out there mainly spectrapure and Dow.

AZDesertRat · 03/14/2007, 05:45 PM

Spectrapure is the undisputed best brand. They spend more time and money on research and development than all other RO vendors combined, and it shows in the quality and uniqueness of their products. Take a look at both their Sponsors Forum here on RC and their website www.spectrapure.com . They offer products you cannot find anywhere else. Read about their MaxCap RO/DI system and what sets it apart and also about their hand tested and guaranteed RO membranes.
Other good vendors are
www.buckeyefieldsupply.com
www.thefilterguys.biz
www.purelyh2o.com

03/13/2007, 06:44 PM	#1
lakwriter Registered Member Join Date: Dec 2006 Location: Pittsburgh Posts: 562	I have ? about RO/DI systems I am considering purchasing an RO/DI system, but I need some help understanding how they are used & installed. I currently use RO water from my LFS. Questions... 1. Are RO/DIs permemantly plumbed in, or can they be connected and disconnected from, say, a laundry tub spigot? 2. Do they come in small capacities, like 5 gallons per day? I don't need a lot of water and I would like to hook up 24 hours before its needed to produce my change water. I don't have room to store many gallons of water. 3. What added value do you get from RO/DI as opposed to just RO? Thanks! __________________ And this, too, shall pass... 29 g FOWLR 37# LR, 35# LS 2 green chromis 2 ocellaris clowns a very social peppermint shrimp and various snails and hermits

03/13/2007, 06:57 PM	#2
mg426 Registered Member Join Date: Jan 2006 Location: maryland Posts: 6,923	RO/DI systems can be very portable. I believe that the best membrane is a 75 gallon/day DOW filmtec. the DI stage removes the remining impurities that the RO cant remove. AZdesertRat will most likely jump in here and answer anything you need to know. __________________ 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

03/13/2007, 07:10 PM	#3
lakwriter Registered Member Join Date: Dec 2006 Location: Pittsburgh Posts: 562	Is it reasonable to hook up the system for a few hours to make the amount of water I want and then disconnect? I can set it up so I can watch it and make sure it doesn't overflow. __________________ And this, too, shall pass... 29 g FOWLR 37# LR, 35# LS 2 green chromis 2 ocellaris clowns a very social peppermint shrimp and various snails and hermits

03/14/2007, 09:39 AM	#6
Pyrrhus Registered Member Join Date: Mar 2004 Location: Tempe, AZ Posts: 2,713	Actually Spectrapure uses industry standard parameters when stating the production of the membranes that they sell. When Dow released the Filmtec membranes they chose to rate them at 50 psi rather than the industry standard of 60 psi. If you rate a Filmtec at the industry standard of 60 psi the GPD rating is significantly higher than the manufacturers stated capacity. __________________ Severe Knowledge In Plumbing

03/14/2007, 04:02 PM	#9
Pyrrhus Registered Member Join Date: Mar 2004 Location: Tempe, AZ Posts: 2,713	The marketing gimmick is actually on the part of Dow, not Spectrapure. __________________ Severe Knowledge In Plumbing

03/13/2007, 07:25 PM	#4
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Membranes generally come in 25, 50 and 75 gallon per day varieties. There are others such as 100 GPD which in some cases is not a real RO membrane but is a nanofilter which is one step below RO and not as efficient. Others include Spectrapures 90 GPD which is similar to a 75 and their new 150 GPD which is the best thing since sliced bread. The biggest advantage of the 75 GPD and up is it makes water much faster than a 25 or 50 GPD, 50% to 300% faster so you don't stand around watching it drip....drip...drip. The cost and the physical size is basically the same between all of them so get the 75. Remember with the smaller on it takes 24 hours to make that quantity and that under perfect conditions which are 77 degree water temperature and 50 to 60 psi incoming pressure which is not always the case. Lower temps and/or pressures affect output and it can cut it 50% or more easily. They can easily be screwed onto a kitchen faucet or a hose bib type connection either outside or next to the washing machine. Waste flows can be reused in a washing machine, in the garden, lawn, pool or any number of good uses. I mounted mine over my laundry sink in the garage so if I forget to shut it off and it overflows it goes into the sink and not on the wifes kitchen floor.....not that I have ever done that before .

03/14/2007, 08:58 AM	#5
Colin Registered Member Join Date: May 2000 Location: Oklahoma City Posts: 848	You can use one of those garden hose "Y" adapters to hook it into the spigot that feeds your washing machine. That way you don't have to continually connect and disconnect your washer. You can also just set the bucket on the washer lid, so that if you do forget, it will just go into the washer tub (I do this all the time). The water will overflow the bucket and go into the crack around the washer lid. Don't bother with anything but a 75G/day. Anything less is a rip-off, and the 100's don't work as well (as mentioned above). The exception is the Spectrapure units like the 90 (which is really a 75), but they seem to make thier own marketing rules when it comes to GPD. --Colin

03/14/2007, 09:59 AM	#7
Colin Registered Member Join Date: May 2000 Location: Oklahoma City Posts: 848	That's true, but it's still a marketing trick. That would apply to any Dow Filmtec membrane. If you're buying Spectrapure just because it's advertised as 90 gal/day instead of 75 gal/day, then you've been had. At any rate, they're still good products. That's reason enough to buy from them. --Colin

03/14/2007, 12:56 PM	#8
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	You buy Spectrapure to get their SpectraSelect individually hand tested and guaranteed 98+% rejection rate RO membranes. No one else offers this individualized service or performance guarantee, no one. Mine is running at over 99% rejection, anywhere between 99.19 and 99.25% to be exact.

03/14/2007, 04:46 PM	#10
lakwriter Registered Member Join Date: Dec 2006 Location: Pittsburgh Posts: 562	Is Spectrapure one of the better brands? What are some other good brands? __________________ And this, too, shall pass... 29 g FOWLR 37# LR, 35# LS 2 green chromis 2 ocellaris clowns a very social peppermint shrimp and various snails and hermits

03/14/2007, 05:23 PM	#11
landfish Registered Member Join Date: Jun 2004 Posts: 29	I have only seen a few brands out there mainly spectrapure and Dow.

03/14/2007, 05:45 PM	#12
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Spectrapure is the undisputed best brand. They spend more time and money on research and development than all other RO vendors combined, and it shows in the quality and uniqueness of their products. Take a look at both their Sponsors Forum here on RC and their website www.spectrapure.com . They offer products you cannot find anywhere else. Read about their MaxCap RO/DI system and what sets it apart and also about their hand tested and guaranteed RO membranes. Other good vendors are www.buckeyefieldsupply.com www.thefilterguys.biz www.purelyh2o.com