RO VS RODI water for reef tank

jimv · 12/03/2012, 11:17 PM

I am setting up a new 34 gallon reef tank. I have never had a reef tank before but had a salt water fish only tank about 10 years ago. I know that RO unit will remove most of the impurities including dissolved solids from the water and that the DI will remove any remaining dissolved solids. Is there any tangible effect on the health of your reef if you only use RO and not DI? Is 10 ppm of TDS that is still in the water after the RO stage going to hurt? It is easier to justify purchasing an under sink RO unit because in addition to being able to use it for the reef tank we can use it as drinking water but am having a harder time justifying a RODI system dedicated to the tank. I also have a whole house sediment/carbon filter and a water softener in line before the proposed location of the RO unit. Any thoughts?

Michigan Mike · 12/03/2012, 11:37 PM

Add a bi-pass valve and use the RO water for drinking and the DI for your tank.

Jpruitt546 · 12/04/2012, 02:47 AM

A 10ppm reading is not bad. I have always used ro/di just to keep the ppm down next to nothing. Anything is better than tap water.

Buckeye Hydro · 12/04/2012, 08:20 AM

Feed softened water to your RODI.

You can get a RODI system configured to send RO water to a pressure tank and drinking water faucet, AND DI water to another outlet for your tank. Becareful if you do this and go with a vendor who is involved in this hobby. There are many mis-configured combo units out there.

Russ

thegrun · 12/04/2012, 08:37 AM

Without an expensive analysis of your water, there is no way to know if the remaining 10 TDS is going to be a major problem or none at all. You could have all kinds of heavy metals in the water, who knows? You will always wonder if the problems you are having with your tank are water purity issues or from another cause. If for no other reason I would not skip the DI resin.

sleepydoc · 12/04/2012, 08:54 AM

+1 to grun's response. 10 TDS is pretty pure, and would probably be fine, but you don't know what the last 10 is composed of. Adding a DI canister is not that much, and if the water is that clean coming out of the RO filter, the DI resin should last quite a while, so the extra expense should be minimal.

jimv · 12/04/2012, 09:01 AM

Thank you for the responses. For the extra cost I do not have a problem adding a DI unit. My primary goal is to have a multiuse system for drinking water and the reef tank. I notice that drinking water systems do not have a DI stage, why is that? Is it just not necessary or not safe? My secondary goal is to have a clean under the counter install. If DI is not drinkable, is there a preferred method to bypass the DI stage. Would you bypass it in line before the under counter storage tank. Could you use the same faucet outlet or need two separate ones? Also, how does the water softener (salt) impact the water quality?

Thank you for the help.

Buckeye Hydro · 12/04/2012, 09:50 AM

RO water for drinking, DI water for your aquarium.

DI water should not contact metal parts, so typically you want two outlets:
RO water to a pressure tank to a faucet
DI water to a tube and atmospheric (unpressurized) tank.

Russ

thegrun · 12/04/2012, 09:59 AM

There is a long lasting debate as to whether there is any harm in drinking DI water. The World Health Organization says there is a long term problem, many scientists say no. DI water does leach minerals and salts from your body. If you drank it all the time it might be a problem, but an occasional glass is fine IMHO. The bottom line is that it does not taste good so the best method is to tee off a line after your RO filter, one leading to your DI filter (with a back flow preventer) and the other leg running to a pressure storage tank also with a BFP (without a storage tank the flow to your dispenser is very slow) and then to your faucet. Check out the Bulk Reef Supply website, they have several videos that show in depth installations and describe the components.

thegrun · 12/04/2012, 10:03 AM

I should add that after years of having the above mentioned system under my kitchen sink I got tired of having to crawl under the sink to change out filters and moved the entire system out into my garage and simply switched to a two stage under the sink filter for drinking water and use the RO/DI system strictly for tank water.

Driver13 · 12/04/2012, 10:10 AM

Been using RO/DI in both swim only and reef tanks for a decade with zero issues.

kenc87 · 12/04/2012, 02:12 PM

Personally I prefer ro/di but I have a good friend who only uses ro and has the probably one of if not the nicest sps tanks you'll ever see so I mean it's kinda up to you.

Augster · 12/04/2012, 02:36 PM

I'm looking at just an RO only unit with drinking water tank/faucet for my girlfriend's apartment to both reduce the required space (it's really tight under her kitchen sink) and use the drinking water faucet for both drinking water as well as top off water for her 34G Solana FOWLR.

I don't need to worry about plumbing some sort of float valve to yet another reservoir underneath the sink (but no space to do so even if I wanted to) or with a manual valve to manually fill a temporary RO/DI container (which would require monitoring its filling to avoid overflow).

Touring · 12/04/2012, 05:23 PM

i read somewhere that you DO NOT want to drink ro/di cause of bacteria but i could be wrong....

sleepydoc · 12/04/2012, 09:02 PM

The concern is not bacteria but other health effects. The WHO issued a report advising against drinking DI water. There is limited data, but it appears to have adverse health effects. In addition, it doesn't taste very good, so it ends up being an expensive way to get bad-tasting water!

If you want purified drinking water, just put a tee with a valve between the RO and DI stages.

NemosNems · 12/04/2012, 09:04 PM

Quote:

Originally Posted by Jpruitt546

A 10ppm reading is not bad. I have always used ro/di just to keep the ppm down next to nothing. Anything is better than tap water.

Depends on what those 10ppm is, if its phosphates or nitrates, than it is pretty bad.

Jpruitt546 · 12/04/2012, 10:51 PM

Nemo that is correct, thats why i prefer ro/di i get 0ppm across all water testing.

GPB · 12/05/2012, 08:07 AM

I have used RO only successfully for the last year. I have 0 PO4 and 0 NO3. At least as far as my test kits show. I actually am trying to get them up to measureable levels.

My TDS before RO is 180. After is 7. I test my source water after RO and don't record any PO4 or Nitrate. There's something in it to make it 7 TDS but I have no idea what that is.

12/03/2012, 11:17 PM	#1
jimv Registered Member Join Date: Dec 2012 Location: Riverview, FL Posts: 5	RO VS RODI water for reef tank I am setting up a new 34 gallon reef tank. I have never had a reef tank before but had a salt water fish only tank about 10 years ago. I know that RO unit will remove most of the impurities including dissolved solids from the water and that the DI will remove any remaining dissolved solids. Is there any tangible effect on the health of your reef if you only use RO and not DI? Is 10 ppm of TDS that is still in the water after the RO stage going to hurt? It is easier to justify purchasing an under sink RO unit because in addition to being able to use it for the reef tank we can use it as drinking water but am having a harder time justifying a RODI system dedicated to the tank. I also have a whole house sediment/carbon filter and a water softener in line before the proposed location of the RO unit. Any thoughts?

12/04/2012, 08:54 AM	#6
sleepydoc Registered Member Join Date: Oct 2011 Location: Minneapolis, MN Posts: 3,907	+1 to grun's response. 10 TDS is pretty pure, and would probably be fine, but you don't know what the last 10 is composed of. Adding a DI canister is not that much, and if the water is that clean coming out of the RO filter, the DI resin should last quite a while, so the extra expense should be minimal. __________________ ~~~~~~~~~~~~~~~~~~~~~ 120 gallon, coast to coast overflow w/beananimal overflow. Waveline DC 10000 II return pump, 40 gal sump, Octopus XS200 skimmer, T5 lighting

12/04/2012, 02:36 PM	#13
Augster Registered Member Join Date: Apr 2012 Location: Sandy Eggo Posts: 197	I'm looking at just an RO only unit with drinking water tank/faucet for my girlfriend's apartment to both reduce the required space (it's really tight under her kitchen sink) and use the drinking water faucet for both drinking water as well as top off water for her 34G Solana FOWLR. I don't need to worry about plumbing some sort of float valve to yet another reservoir underneath the sink (but no space to do so even if I wanted to) or with a manual valve to manually fill a temporary RO/DI container (which would require monitoring its filling to avoid overflow). __________________ New builds in progress: JBJ 45, DIY 17G Sump, DIY ATS Current Tank Info: JBJ 45, 20 pounds Pukani

12/04/2012, 09:02 PM	#15
sleepydoc Registered Member Join Date: Oct 2011 Location: Minneapolis, MN Posts: 3,907	The concern is not bacteria but other health effects. The WHO issued a report advising against drinking DI water. There is limited data, but it appears to have adverse health effects. In addition, it doesn't taste very good, so it ends up being an expensive way to get bad-tasting water! If you want purified drinking water, just put a tee with a valve between the RO and DI stages. __________________ ~~~~~~~~~~~~~~~~~~~~~ 120 gallon, coast to coast overflow w/beananimal overflow. Waveline DC 10000 II return pump, 40 gal sump, Octopus XS200 skimmer, T5 lighting

12/05/2012, 08:07 AM	#18
GPB Registered Member Join Date: Sep 2004 Location: Washington DC Posts: 633	I have used RO only successfully for the last year. I have 0 PO4 and 0 NO3. At least as far as my test kits show. I actually am trying to get them up to measureable levels. My TDS before RO is 180. After is 7. I test my source water after RO and don't record any PO4 or Nitrate. There's something in it to make it 7 TDS but I have no idea what that is. __________________ It is what it is! Current Tank Info: Oceanic 37g cube, AquaC Remora Skimmer, 6 x T5 ligts, SSB, 10g sump, GFO, GAC, Polyfilter

12/03/2012, 11:37 PM	#2
Michigan Mike Freedom costs a buckofive Join Date: May 2012 Location: Michigan Posts: 3,002	Add a bi-pass valve and use the RO water for drinking and the DI for your tank.

12/04/2012, 02:47 AM	#3
Jpruitt546 Registered Member Join Date: Dec 2012 Location: Sherman TX Posts: 74	A 10ppm reading is not bad. I have always used ro/di just to keep the ppm down next to nothing. Anything is better than tap water.

12/04/2012, 08:20 AM	#4
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	Feed softened water to your RODI. You can get a RODI system configured to send RO water to a pressure tank and drinking water faucet, AND DI water to another outlet for your tank. Becareful if you do this and go with a vendor who is involved in this hobby. There are many mis-configured combo units out there. Russ

12/04/2012, 08:37 AM	#5
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	Without an expensive analysis of your water, there is no way to know if the remaining 10 TDS is going to be a major problem or none at all. You could have all kinds of heavy metals in the water, who knows? You will always wonder if the problems you are having with your tank are water purity issues or from another cause. If for no other reason I would not skip the DI resin.

12/04/2012, 09:01 AM	#7
jimv Registered Member Join Date: Dec 2012 Location: Riverview, FL Posts: 5	Thank you for the responses. For the extra cost I do not have a problem adding a DI unit. My primary goal is to have a multiuse system for drinking water and the reef tank. I notice that drinking water systems do not have a DI stage, why is that? Is it just not necessary or not safe? My secondary goal is to have a clean under the counter install. If DI is not drinkable, is there a preferred method to bypass the DI stage. Would you bypass it in line before the under counter storage tank. Could you use the same faucet outlet or need two separate ones? Also, how does the water softener (salt) impact the water quality? Thank you for the help.

12/04/2012, 09:50 AM	#8
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	RO water for drinking, DI water for your aquarium. DI water should not contact metal parts, so typically you want two outlets: RO water to a pressure tank to a faucet DI water to a tube and atmospheric (unpressurized) tank. Russ

12/04/2012, 09:59 AM	#9
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	There is a long lasting debate as to whether there is any harm in drinking DI water. The World Health Organization says there is a long term problem, many scientists say no. DI water does leach minerals and salts from your body. If you drank it all the time it might be a problem, but an occasional glass is fine IMHO. The bottom line is that it does not taste good so the best method is to tee off a line after your RO filter, one leading to your DI filter (with a back flow preventer) and the other leg running to a pressure storage tank also with a BFP (without a storage tank the flow to your dispenser is very slow) and then to your faucet. Check out the Bulk Reef Supply website, they have several videos that show in depth installations and describe the components.

12/04/2012, 10:03 AM	#10
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	I should add that after years of having the above mentioned system under my kitchen sink I got tired of having to crawl under the sink to change out filters and moved the entire system out into my garage and simply switched to a two stage under the sink filter for drinking water and use the RO/DI system strictly for tank water.

12/04/2012, 10:10 AM	#11
Driver13 Moved On Join Date: Mar 2006 Posts: 53	Been using RO/DI in both swim only and reef tanks for a decade with zero issues.

12/04/2012, 02:12 PM	#12
kenc87 Registered Member Join Date: Feb 2012 Location: Ypsilanti, MI Posts: 610	Personally I prefer ro/di but I have a good friend who only uses ro and has the probably one of if not the nicest sps tanks you'll ever see so I mean it's kinda up to you.

12/04/2012, 05:23 PM	#14
Touring Registered Member. Join Date: Apr 2012 Location: Panhandle Posts: 724	i read somewhere that you DO NOT want to drink ro/di cause of bacteria but i could be wrong....

12/04/2012, 10:51 PM	#17
Jpruitt546 Registered Member Join Date: Dec 2012 Location: Sherman TX Posts: 74	Nemo that is correct, thats why i prefer ro/di i get 0ppm across all water testing.