RO/DI Water

Falconeer · 12/25/2009, 09:33 PM

Hi all, I've recently been thinking about getting my own RODI unit, but I realized that they sell both RO units and RODI units.

I now about the issue of humans drinking RO vs. RODI water, but does adding the DI to a unit really make that big of a difference? I can ask when i'm in tomorrow, but I believe my LFS only uses an RO unit. At very least, they only label it RO.

Would it be a big problem to use a plain RO unit rather than an RODI unit?

Thanks,
Falc

AzCondor · 12/25/2009, 09:41 PM

I am no expert but from what the guy at our local water store said was that a good RO system is just as good as RODI water. His RO water is pure water, no particles, so how would RODI be any purer? I think a more important thing would be use the ozone sterilizers they have there for cleaning your containers . Having a clean container is probably more important than the jump from RO to RODI. Just my 2 cents.

DC_40gallon · 12/25/2009, 09:45 PM

Ro will make you amazing drinking water, rodi will make you 100% virgin zero tds water which is what you want for your tank.

Falconeer · 12/25/2009, 09:49 PM

Ok, well if it just comes down to the TDS reading, then I suppose it would be different from house-to-house as to whether or not an RO unit was good enough (and of course, the cleanliness of your holding container), no?

I do really like good drinking water though, especially with my new water bottle at hand, haha!

Thanks for the responses, i'm thinking I may want to purchase a TDS meter? I think i'll need it eventually

Thanks,
Falc

teesquare · 12/25/2009, 09:50 PM

The pupose of the DI portion of a RO/DI system is to remove the rest of the phosphate and silicates tha cannot be completely removed by RO alone. Period.
I own a pumped 300 gpd Dow Filmtec 6 stage RO unit. And the meter constant said "0" TDS -And even then it made a difference by using a good quality DI cartidge after the RO to "polish" the product water.

If have any concerns about phosphate and the algaes they can feed

- then WHY cheap the deal? spend the SMALL amount extra for the DI added to your RO.
T

AzCondor · 12/25/2009, 09:56 PM

Is it possible to get a 0 TDS reading off of a really high end RO system like at a water store? Or is this guy at the store full of it when he says its zero?

Falconeer · 12/25/2009, 10:01 PM

Quote:

Originally Posted by teesquare

The pupose of the DI portion of a RO/DI system is to remove the rest of the phosphate and silicates tha cannot be completely removed by RO alone. Period.
I own a pumped 300 gpd Dow Filmtec 6 stage RO unit. And the meter constant said "0" TDS -And even then it made a difference by using a good quality DI cartidge after the RO to "polish" the product water.

If have any concerns about phosphate and the algaes they can feed

- then WHY cheap the deal? spend the SMALL amount extra for the DI added to your RO.
T

Ok, that makes sense. I'm looking at smaller systems (50-75 GPD), where the DI part seems like it's a lot more, or at least with the systems i'm looking at they are.

teesquare · 12/25/2009, 10:03 PM

Well it is a reasonable question to ask of the water store guy...
Because the TDS meters in use are almost never that accurate, all of the time. And - what is the affinity range of the meter? Does it measure .5 ppm as zero? Or .9?

So - I guess my point is that water store folks are dealing with typical uses for tap water. We are "geeks" and really need better than what we would drink for our tanks to have the best opportunity to thrive.
Basically - I operate under the theory that anything I can eliminate going into the tank that is not known or quantifiable may prevent more problems figuring out what is wrong in the future. Make sense?
T

teesquare · 12/25/2009, 10:05 PM

You may want to ck out Bulk Reef Supply for RO/DI systems. They also sell the DI resins so you can refill your own cartridge and save some money.
T

Falconeer · 12/25/2009, 10:06 PM

Ok. I'd been looking at The Filter Guys and....I feel so ashamed but....Petsmart has a 50GPD RO unit that I was going to look more into to see if it was worth spit.

AzCondor · 12/25/2009, 10:08 PM

Ya that makes sense, he just made his expensive system seem like it eliminated the need to get RODI water. Where I live there is a real lack of anywhere to get great water. I was using the water vending machine because that was all we had. Now this guy opened and it seems better than a water vending machine...

Rybren · 12/25/2009, 10:15 PM

I have a 5 stage BRS Chloramine unit. My tap water is 75 TDS and I get 0 TDS after the RO, but still run my tank water through the DI to remove the ammonia that gets released from the breakdown of the chloramine. From what I understand after reading articles by RHF and others, the RO alone won't remove the ammonia. I take their word on it. Just something to consider if your source water contains chloramines.

teesquare · 12/25/2009, 10:17 PM

Just a thought...
If you spring for a larger unit, you can have all the water you need for the tank, and clean drinking and cooking water for the family! You can get a unit with a tap for the sink, and a pressure tap - and away you go!
As well - there are units that have a much lower rejection rate, and that save on waste water - which you are paying for.
The Filter Guys make great equipment as well. I forgot to mention them.
T

lordofthereef · 12/25/2009, 10:42 PM

Quote:

Originally Posted by AzCondor

Is it possible to get a 0 TDS reading off of a really high end RO system like at a water store? Or is this guy at the store full of it when he says its zero?

It depends on what the incoming water is like. If it is relatively pure, I wouldn't doubt that all you need is a 3-4 stage RO. The DI is simply to polish off the leftovers. I will say that it is relatively rare to have a situation like this. Most people have well over 100 TDS going in and this will still leaved 2-3 TDS just going through the RO. It is also said not to drink DI water because it is devoid of any minerals and the like. Frankly, the minerals we get from our water we should be getting elsewhere. I doubt that anyone here is getting their required daily intake of any mineral strictly from their water supply.

lordofthereef · 12/25/2009, 10:44 PM

Quote:

Originally Posted by Rybren

I have a 5 stage BRS Chloramine unit. My tap water is 75 TDS and I get 0 TDS after the RO, but still run my tank water through the DI to remove the ammonia that gets released from the breakdown of the chloramine. From what I understand after reading articles by RHF and others, the RO alone won't remove the ammonia. I take their word on it. Just something to consider if your source water contains chloramines.

If you have ammonia in your water it should still be reading higher than 0 TDS unless your meter is just not sensitive enough to read it.

AzCondor · 12/25/2009, 10:47 PM

Well I live in northern arizona and we have really good tap water I think it somewhere around 75 tds. Since this guy is my only source I guess I m stuck with him. I live in an apartment is it possible to hook up an RODI system in there (logistically)?

Chris27 · 12/25/2009, 11:09 PM

I run a Carbon / DI filter. The 2 canisters are about 20" long, and hold a great deal of carbon and DI resin. On average, I swap out the carbon cartridge after about 2000 Gal, and the DI cartridge every 400 Gal. I always have 0 TDS, get over a gal / min of pure water, and don't have a drop of waste water. It's a great way to go, and the equipment is very simple to use. Basically you just use two single canisters, one for carbon, one for DI. This system works great for the low TDS tap water we have here.

fixx198 · 12/26/2009, 01:50 AM

I live in Florida. My incoming TDS after the cotton pre filter runs 315 to 375. I run 0.0 TDS after the RODI. I did notice once when i was learning that my DI went Bad and my TDS was about 13 to 30. Since this was my top off water my corals started to close up. zoos where closed for weeks and star Polyp would not extend. Now as soon as the TDS output says .1 i change my DI filter.
So with that being said. If you can get 0.0 TDS out of your water filter system then you should be fine.

Steve

Lightsluvr · 12/26/2009, 03:14 AM

Quote:

Originally Posted by AzCondor

Ya that makes sense, he just made his expensive system seem like it eliminated the need to get RODI water. Where I live there is a real lack of anywhere to get great water. I was using the water vending machine because that was all we had. Now this guy opened and it seems better than a water vending machine...

You probably understand the term "Bravo Sierra"...

That's what the "Water store" is serving...

If you are just keeping fish - RO is probably fine. If you want SPS coral, get your own small RO/DI system from a reputable dealer like the Filter Guys, Bulk Reef Supply or Air, Water, Ice. They are all sponsors here on RC.

Good luck and welcome to the hobby.

LL

Lightsluvr · 12/26/2009, 03:17 AM

Quote:

Originally Posted by AzCondor

Well I live in northern arizona and we have really good tap water I think it somewhere around 75 tds. Since this guy is my only source I guess I m stuck with him. I live in an apartment is it possible to hook up an RODI system in there (logistically)?

LL

lordofthereef · 12/26/2009, 04:44 AM

Wow, I think that wins for most creative RO setup

Do I have permission to link to that when I see someone say "I live in an apartment and therefor cannot install and RO unit."?

Rybren · 12/26/2009, 08:58 AM

If you have ammonia in your water it should still be reading higher than 0 TDS unless your meter is just not sensitive enough to read it.

Having never tested the post-RO water for ammonia, I can't say for sure that there is still some in the water. If it is present, I'll take your word for it that it should register on a sensitive enough TDS meter. As I mentioned, water destined for my tank still goes through the DI stage, and I'm pretty sure that any residual ammonia will be stripped away.

lordofthereef · 12/26/2009, 09:04 AM

Quote:

Originally Posted by Rybren

If you have ammonia in your water it should still be reading higher than 0 TDS unless your meter is just not sensitive enough to read it.

Having never tested the post-RO water for ammonia, I can't say for sure that there is still some in the water. If it is present, I'll take your word for it that it should register on a sensitive enough TDS meter. As I mentioned, water destined for my tank still goes through the DI stage, and I'm pretty sure that any residual ammonia will be stripped away.

Really anything dissolved in the water should read something on the meter. It is basically a conductivity test where pure H2O is not conductive.

dreko · 12/26/2009, 01:36 PM

Hey Falc,
just get the RODI unit, spend the extra $$

AzCondor · 12/26/2009, 03:13 PM

that system is awesome, i think i will do something similar when i get some more money!!

12/25/2009, 09:33 PM	#1
Falconeer Can I get another tank? Join Date: Aug 2009 Location: Wilmette Posts: 330	RO/DI Water Hi all, I've recently been thinking about getting my own RODI unit, but I realized that they sell both RO units and RODI units. I now about the issue of humans drinking RO vs. RODI water, but does adding the DI to a unit really make that big of a difference? I can ask when i'm in tomorrow, but I believe my LFS only uses an RO unit. At very least, they only label it RO. Would it be a big problem to use a plain RO unit rather than an RODI unit? Thanks, Falc

12/25/2009, 09:41 PM	#2
AzCondor Registered Member Join Date: Jul 2009 Posts: 72	I am no expert but from what the guy at our local water store said was that a good RO system is just as good as RODI water. His RO water is pure water, no particles, so how would RODI be any purer? I think a more important thing would be use the ozone sterilizers they have there for cleaning your containers . Having a clean container is probably more important than the jump from RO to RODI. Just my 2 cents. __________________ Vegetarian-A bad hunter. Someone who survives by consuming not food, but the stuff that food eats. The vegetarian was forced to subsist on slower prey, such as the broccoli and carrot.

12/25/2009, 09:50 PM	#5
teesquare Coral Curmudgeon Join Date: Dec 2001 Location: western NC Posts: 1,663	The pupose of the DI portion of a RO/DI system is to remove the rest of the phosphate and silicates tha cannot be completely removed by RO alone. Period. I own a pumped 300 gpd Dow Filmtec 6 stage RO unit. And the meter constant said "0" TDS -And even then it made a difference by using a good quality DI cartidge after the RO to "polish" the product water. If have any concerns about phosphate and the algaes they can feed - then WHY cheap the deal? spend the SMALL amount extra for the DI added to your RO. T __________________ No....really honey, it was a gift! Current Tank Info: 700 gallon combined reef/frag systems - 650gal Cichlid system

12/25/2009, 09:56 PM	#6
AzCondor Registered Member Join Date: Jul 2009 Posts: 72	Is it possible to get a 0 TDS reading off of a really high end RO system like at a water store? Or is this guy at the store full of it when he says its zero? __________________ Vegetarian-A bad hunter. Someone who survives by consuming not food, but the stuff that food eats. The vegetarian was forced to subsist on slower prey, such as the broccoli and carrot.

12/25/2009, 10:03 PM	#8
teesquare Coral Curmudgeon Join Date: Dec 2001 Location: western NC Posts: 1,663	Well it is a reasonable question to ask of the water store guy... Because the TDS meters in use are almost never that accurate, all of the time. And - what is the affinity range of the meter? Does it measure .5 ppm as zero? Or .9? So - I guess my point is that water store folks are dealing with typical uses for tap water. We are "geeks" and really need better than what we would drink for our tanks to have the best opportunity to thrive. Basically - I operate under the theory that anything I can eliminate going into the tank that is not known or quantifiable may prevent more problems figuring out what is wrong in the future. Make sense? T __________________ No....really honey, it was a gift! Current Tank Info: 700 gallon combined reef/frag systems - 650gal Cichlid system

12/25/2009, 09:45 PM	#3
DC_40gallon Registered Member Join Date: Sep 2009 Posts: 1,474	Ro will make you amazing drinking water, rodi will make you 100% virgin zero tds water which is what you want for your tank.

12/25/2009, 09:49 PM	#4
Falconeer Can I get another tank? Join Date: Aug 2009 Location: Wilmette Posts: 330	Ok, well if it just comes down to the TDS reading, then I suppose it would be different from house-to-house as to whether or not an RO unit was good enough (and of course, the cleanliness of your holding container), no? I do really like good drinking water though, especially with my new water bottle at hand, haha! Thanks for the responses, i'm thinking I may want to purchase a TDS meter? I think i'll need it eventually Thanks, Falc

12/25/2009, 10:05 PM	#9
teesquare Coral Curmudgeon Join Date: Dec 2001 Location: western NC Posts: 1,663	You may want to ck out Bulk Reef Supply for RO/DI systems. They also sell the DI resins so you can refill your own cartridge and save some money. T __________________ No....really honey, it was a gift! Current Tank Info: 700 gallon combined reef/frag systems - 650gal Cichlid system

12/25/2009, 10:06 PM	#10
Falconeer Can I get another tank? Join Date: Aug 2009 Location: Wilmette Posts: 330	Ok. I'd been looking at The Filter Guys and....I feel so ashamed but....Petsmart has a 50GPD RO unit that I was going to look more into to see if it was worth spit.

12/25/2009, 10:08 PM	#11
AzCondor Registered Member Join Date: Jul 2009 Posts: 72	Ya that makes sense, he just made his expensive system seem like it eliminated the need to get RODI water. Where I live there is a real lack of anywhere to get great water. I was using the water vending machine because that was all we had. Now this guy opened and it seems better than a water vending machine... __________________ Vegetarian-A bad hunter. Someone who survives by consuming not food, but the stuff that food eats. The vegetarian was forced to subsist on slower prey, such as the broccoli and carrot.

12/25/2009, 10:15 PM	#12
Rybren Registered Member Join Date: Apr 2009 Location: Ottawa, Canada Posts: 1,642	I have a 5 stage BRS Chloramine unit. My tap water is 75 TDS and I get 0 TDS after the RO, but still run my tank water through the DI to remove the ammonia that gets released from the breakdown of the chloramine. From what I understand after reading articles by RHF and others, the RO alone won't remove the ammonia. I take their word on it. Just something to consider if your source water contains chloramines.

12/25/2009, 10:17 PM	#13
teesquare Coral Curmudgeon Join Date: Dec 2001 Location: western NC Posts: 1,663	Just a thought... If you spring for a larger unit, you can have all the water you need for the tank, and clean drinking and cooking water for the family! You can get a unit with a tap for the sink, and a pressure tap - and away you go! As well - there are units that have a much lower rejection rate, and that save on waste water - which you are paying for. The Filter Guys make great equipment as well. I forgot to mention them. T __________________ No....really honey, it was a gift! Current Tank Info: 700 gallon combined reef/frag systems - 650gal Cichlid system

12/25/2009, 10:47 PM	#16
AzCondor Registered Member Join Date: Jul 2009 Posts: 72	Well I live in northern arizona and we have really good tap water I think it somewhere around 75 tds. Since this guy is my only source I guess I m stuck with him. I live in an apartment is it possible to hook up an RODI system in there (logistically)? __________________ Vegetarian-A bad hunter. Someone who survives by consuming not food, but the stuff that food eats. The vegetarian was forced to subsist on slower prey, such as the broccoli and carrot.

12/25/2009, 11:09 PM	#17
Chris27 Registered Member Join Date: Sep 2009 Location: Virginia Beach, VA Posts: 4,452	I run a Carbon / DI filter. The 2 canisters are about 20" long, and hold a great deal of carbon and DI resin. On average, I swap out the carbon cartridge after about 2000 Gal, and the DI cartridge every 400 Gal. I always have 0 TDS, get over a gal / min of pure water, and don't have a drop of waste water. It's a great way to go, and the equipment is very simple to use. Basically you just use two single canisters, one for carbon, one for DI. This system works great for the low TDS tap water we have here.

12/26/2009, 01:50 AM	#18
fixx198 Premium Member Join Date: Dec 2007 Location: Sarasota, FL Posts: 155	I live in Florida. My incoming TDS after the cotton pre filter runs 315 to 375. I run 0.0 TDS after the RODI. I did notice once when i was learning that my DI went Bad and my TDS was about 13 to 30. Since this was my top off water my corals started to close up. zoos where closed for weeks and star Polyp would not extend. Now as soon as the TDS output says .1 i change my DI filter. So with that being said. If you can get 0.0 TDS out of your water filter system then you should be fine. Steve

12/26/2009, 04:44 AM	#21
lordofthereef One reef to rule them all Join Date: Sep 2009 Location: Leominster, MA Posts: 5,299	Wow, I think that wins for most creative RO setup Do I have permission to link to that when I see someone say "I live in an apartment and therefor cannot install and RO unit."? __________________ "A dog is the only thing on earth that loves you more than you love yourself" ~ Josh Billings Visit My Home page for current build thread (click my user name and select "Visit LordoftheReef's Homepage" in the drop down menu!

12/26/2009, 08:58 AM	#22
Rybren Registered Member Join Date: Apr 2009 Location: Ottawa, Canada Posts: 1,642	If you have ammonia in your water it should still be reading higher than 0 TDS unless your meter is just not sensitive enough to read it. Having never tested the post-RO water for ammonia, I can't say for sure that there is still some in the water. If it is present, I'll take your word for it that it should register on a sensitive enough TDS meter. As I mentioned, water destined for my tank still goes through the DI stage, and I'm pretty sure that any residual ammonia will be stripped away.

12/26/2009, 01:36 PM	#24
dreko Registered Member Join Date: Jan 2004 Location: NY Posts: 79	Hey Falc, just get the RODI unit, spend the extra $$

12/26/2009, 03:13 PM	#25
AzCondor Registered Member Join Date: Jul 2009 Posts: 72	that system is awesome, i think i will do something similar when i get some more money!! __________________ Vegetarian-A bad hunter. Someone who survives by consuming not food, but the stuff that food eats. The vegetarian was forced to subsist on slower prey, such as the broccoli and carrot.