RO/DI question

Jl330 · Jul 10, 2018

Is the DI stage really necessary? My wife wants an RO drinking water system and I'm wondering if I can use it for the tank.

chefjpaul · Jul 10, 2018

Pretty much..yes.

You can hook up both from a single unit, diverting the ro to a separate reservoir.

Look at this website for diagrams etc.

http://spectrapure.com/hookup-diagrams

Jl330 · Jul 10, 2018

chefjpaul said:
Pretty much..yes.

You can hook up both from a single unit, diverting the ro to a separate reservoir.

Look at this website for diagrams etc.

http://spectrapure.com/hookup-diagrams

So is basic RO water fine for the tank without the deionized properties, or am I reading wrong?

chefjpaul · Jul 10, 2018

Jl330 said:
So is basic RO water fine for the tank without the deionized properties, or am I reading wrong?

No, you WILL want tge DI for your tank.

Split the line before the DI for drinking Ro

PatW · Jul 10, 2018

RO water beats tap water. But it could still contain toxic metals like copper and lead. Since one uses water to top off the tank as well as mixing salt water, any toxic additions will tend to accumulate. Of course, some people use tap water. And the unfortunate example in Flint, MI shows us that some public water systems and the people who run them are not to be trusted.

chipmunkofdoom2 · Jul 10, 2018

You might be able to get away with RO only water, but that depends entirely on the chemistry of your source water. A majority of the ions that cause problems in reef tanks (copper, ammonia, phosphate and silicate) all are handled by the DI resin. If you don't have DI resin, these are all going in your tank.

Is this "fine," as you put it? It depends how much of these elements are in your source water. People spend thousands of dollars on corals, fish, live rock and live sand. That doesn't include how much we spend on tanks, stands, lights, salt mix and pumps. I don't think putting all that at risk to save $20 on DI resin every few months is worth it. I'm all about saving money, but this hobby is more about keeping water than keeping fish or corals. I'd look to save money on something else besides water.

Jl330 · Jul 10, 2018

chefjpaul said:
No, you WILL want tge DI for your tank.

Split the line before the DI for drinking Ro

Got ya. Is that an option with all units?

I have a convenient layout in my house where my kitchen sink shares a wall with the garage and there's a water line out there. I can set up the unit out there and then run a line inside to the sink and have my drinking water in there and then my tank water feeding out there.

Will a 50 gal system be adequate to support drinking water?

miPapareef · Jul 10, 2018

You don’t have to choose between an RO drinking water system or an RODI aquarium system. I use one system for both purposes. It came with a tee and a valve so that you can take the RO water for drinking.

I would certainly recommend an RODI system for the aquarium.

miPapareef · Jul 10, 2018

Jl330 said:
Will a 50 gal system be adequate to support drinking water?

50 gallons per day is a very slow trickle of water and you won’t want to wait each time you need a drink.

You can get a pressurized tank to hold a couple gallons. https://www.bulkreefsupply.com/reverse-osmosis-pressurized-tank.html

Opus · Jul 10, 2018

Just buy a system like this: Any of the RO/DI sponsors on here will sell a system like this.

https://www.bulkreefsupply.com/6-stage-75-gpd-drinking-reef-ro-di-system-brs.html

Greybeard · Jul 10, 2018

You can do both... I do

My incoming water line runs through a prefilter, then a 5 micron carbon block, then a 1 micron carbon block, then the RO membrane, then a permeate pump, to keep the clean water pressure up where it needs to be. From there, it 'T's off. One line runs to a 5g pressure tank, that feeds a drinking water faucet at my kitchen sink, and my refrigerator ice maker/water dispenser. That line has a check valve on it, to keep water from the pressure tank from feeding back to the RO/DI system, and a final inline carbon filter, to give the drinking water a final polish. The other leg of the T, after the premate pump, runs to a 2 stage DI setup, and on to my sump closet, where it feeds my mixing station, my ATO reservoir's auto refill system, and a manual valve on a short roll of hose, for miscellaneous water needs.

You don't want to drink DI water... if for no other reason, than because you'd burn through a fortune in DI resin

RO gives you the great tasting water you want, and crystal clear ice cubes. You don't want RO water, without the DI pass, in your tank, because that DI cartridge removes a significant source of unknown contaminates that can and will cause problems in a reef.

My system, with most of the components I've mentioned, though I've upgraded it a bit, came from AirWaterIce, and is available under the name 'dual home/reef'. I highly recommend AirWaterIce. Well designed, great quality stuff, reasonable prices, and excellent support, should you need it.

Jl330 · Jul 10, 2018

Greybeard said:
You can do both... I do

My incoming water line runs through a prefilter, then a 5 micron carbon block, then a 1 micron carbon block, then the RO membrane, then a premate pump, to keep the clean water pressure up where it needs to be. From there, it 'T's off. One line runs to a 5g pressure tank, that feeds a drinking water faucet at my kitchen sink, and my refrigerator ice maker/water dispenser. That line has a check valve on it, to keep water from the pressure tank from feeding back to the RO/DI system, and a final inline carbon filter, to give the drinking water a final polish. The other leg of the T, after the premate pump, runs to a 2 stage DI setup, and on to my sump closet, where it feeds my mixing station, my ATO reservoir's auto refill system, and a manual valve on a short roll of hose, for miscellaneous water needs.

You don't want to drink DI water... if for no other reason, than because you'd burn through a fortune in DI resin RO gives you the great tasting water you want, and crystal clear ice cubes. You don't want RO water, without the DI pass, in your tank, because that DI cartridge removes a significant source of unknown contaminates that can and will cause problems in a reef.

My system, with most of the components I've mentioned, though I've upgraded it a bit, came from AirWaterIce, and is available under the name 'dual home/reef'. I highly recommend AirWaterIce. Well designed, great quality stuff, reasonable prices, and excellent support, should you need it.

You answered my next question. My wife doesn't want the extra drinking water spout so I was thinking I could have the line just run to the fridge and we could get our water from there. Win/win

Clear ice is a bonus. lol

Greybeard · Jul 10, 2018

Jl330 said:
You answered my next question. My wife doesn't want the extra drinking water spout so I was thinking I could have the line just run to the fridge and we could get our water from there. Win/win

Clear ice is a bonus. lol

Note: Most modern refrigerators require a fair amount of pressure to feed the water/ice dispenser. A pressure tank is a necessity, and you're probably going to want to investigate a permeate pump, as well. If you're unfamiliar with them, it's a mechanical device that does two things: First, they increase outgoing (clean) water pressure to match that of the incoming water pressure. Normally, you'll loose quite a bit of pressure on the clean side of an RO membrane. Second, they act as a replacement for the more typical 'Auto Shut Off Valve' (ASOV) that RO/DI units come with. As pressure equalizes, the pump stops both clean water and waste water coming from the RO membrane, so incoming water is no longer flowing, though still under full pressure. I don't trust ASOV's. Had one too many failures with them. I _always_ want a permeate pump on my RO systems, even if I don't need the higher pressure they produce. They're not terribly expensive, and are MUCH more reliable than any ASOV I've ever owned.

skim · Jul 10, 2018

This will give a rough idea what a good quality membrane will remove. This why it is important to purchase a name brand membrane's like DOW. It will remove up to 90% to 99% of the unwanted things and then the DI will remove the final minute amounts and give you the pure water. If membrane is not removing or performing as it should you will find yourself going through large amounts of DI resins. The membrane is the heart of the system and does the most work so prefiltering with good Carbon blocks and Sediment Filter is very important.

Estimated Reverse Osmosis Rejection Percentages
The reverse osmosis process uses a semi-permeable membrane to reject a wide variety of impurities. Here is a partial list.

Aluminum 97-98% Nickel 97-99%
Ammonium 85-95% Nitrate 93-96%
Arsenic 94-96% Phosphate 99+%
Bacteria 99+% Polyphosphate 98-99%
Bicarbonate 95-96% Potassium 92%
Boron 50-70% Pyrogen 99+%
Bromide 93-96% Radioactivity 95-98%
Cadmium 96-98% Radium 97%
Calcium 96-98% Selenium 97%
Chloride 94-95% Silica 85-90%
Chromate 90-98% Silicate 95-97%
Chromium 96-98% Silver 95-97%
Copper 97-99% Sodium 92-98%
Cyanide 90-95% Sulphate 99+%
Ferrocyanide 98-99% Sulphite 96-98%
Fluoride 94-96% Zinc 98-99%
Iron 98-99%
Lead 96-98% Insecticides 97%
Magnesium 96-98% Detergents 97%
Manganese 96-98% Herbicides 97%
Mercury 96-98% Virus 99+%
TDS (Total Dissolved Solids) 95-99% Hardness 93-97%
Figures given above are not actual test figures, but are manufacturer estimates of normal TFC membrane performance.

Buckeye Hydro · Jul 10, 2018

Our Reef/Residential RODI systems deliver RO water to a pressurized drinking water tank, and then to a faucet; and also DI water for your tank.
http://www.buckeyehydro.com/content/5_Stage_Reef_Residential_RODI.pdf

http://www.buckeyehydro.com/reef-residential-rodi/

sghera64 · Jul 10, 2018

Jl330 said:
Is the DI stage really necessary? My wife wants an RO drinking water system and I'm wondering if I can use it for the tank.

I stopped using the DI cartridge about 2 years ago and don't have any problems. BUT!!! My RO water comes out at 0-2 PPM TDS. AND, most of my top-off water passes through a Kalk reactor. I also grow a lot of macro algae and that might be consume some elements (metals, phosphate, nitrate, ammonia) and then it exits the system when I periodically "prune" it back.

Since the pH in the kalk reactor is so high, many of the "bad" stuff is precipitated out (e.g. iron, copper, phosphate). Then, (call me crazy), I have to add this "junk" back to the system as I dose nitrate and phosphate lest they drop so low I get cyano, poor SPS coloration and other symptoms of water that is "too clean".

If I'm not mistaken, my trace elements contain iron, copper, manganese and many popular salt brands contain these too [LINK].

I'm not saying going without DI is the right answer, but it can work. And, as others mentioned, it does depend on what is in your source water and what are your home plumbing pipes made of (iron, copper, lead, PVC, bamboo). Also, you could send your RO water in for a ICP-MS analysis as well to get a better idea to what extent you would be adding "contaminants".

Buckeye Hydro · Jul 11, 2018

Or a copper shading ring in a solenoid valve

Jl330 · Jul 12, 2018

I got a unit ordered through a forum member. Thanks guys. I'll be setup and making water very soon.

Also ordered an ATO. If only my tank was close to my unit. I don't think my wife would appreciate me turning our downstairs bathroom into a fish room.

jk_s124 · Aug 30, 2020

Greybeard said:
Note: Most modern refrigerators require a fair amount of pressure to feed the water/ice dispenser. A pressure tank is a necessity, and you're probably going to want to investigate a permeate pump, as well. If you're unfamiliar with them, it's a mechanical device that does two things: First, they increase outgoing (clean) water pressure to match that of the incoming water pressure. Normally, you'll loose quite a bit of pressure on the clean side of an RO membrane. Second, they act as a replacement for the more typical 'Auto Shut Off Valve' (ASOV) that RO/DI units come with. As pressure equalizes, the pump stops both clean water and waste water coming from the RO membrane, so incoming water is no longer flowing, though still under full pressure. I don't trust ASOV's. Had one too many failures with them. I _always_ want a permeate pump on my RO systems, even if I don't need the higher pressure they produce. They're not terribly expensive, and are MUCH more reliable than any ASOV I've ever owned.

Sorry @Greybeard, I know this is an old post, but I’m hoping you can help me a bit to understand where to put a permeate pump in a brs drinking water/reef RODI system. You say that the permeate pump replaces the auto shut off valve. Does it get plumbed into the same spot that the auto shut off valve in a typical BRS system is found? And do you place the check valve before or after the final carbon block on your drinking water line?

KStatefan · Aug 31, 2020

jk_s124 said:
Sorry @Greybeard, I know this is an old post, but I’m hoping you can help me a bit to understand where to put a permeate pump in a brs drinking water/reef RODI system. You say that the permeate pump replaces the auto shut off valve. Does it get plumbed into the same spot that the auto shut off valve in a typical BRS system is found? And do you place the check valve before or after the final carbon block on your drinking water line?

The check valve should be before the RO water goes to the pressure tank. The taste and odor carbon filter should be on the line to the dispenser. I have never had an auto shut off valve but here is a picture of my hookup. The check valve is located to the right of the y fitting. The top line goes to the DI system and bottom line to the drinking water tank.