Love RODI But Hate The Waste? Here’s The Solution With Side Benefits

One of the largest complaints people have about reverse osmosis deionization units is the amount of waste water they produce. Usually the waste water can be stored and recycled for other uses such as watering plants or lawns. However, not all of us (that includes me), have the capabilities to save the waste water.

So if you want to keep your RODI water for the great things it does for your saltwater tank, but want to cut the waste, here’s the solution. Did I mention it had another great side benefit as well?

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Comments for this article (67)

  • Merne says:

    Great tip! I’ve been feeling guilty about all that waste water.

  • Landon says:

    Nice tip. Your tank seems to be coming along very well.

  • Chris Kennedy says:

    A Great is a good and easy make good water so much faster.i add the booster pump to.i have a 35 gallon storage can i use and it fill it in 2 1/2 hours to 3 hours. i do have a Question BRS sell 75 GPD Flow Restrictor with Quick Fittings and 100 GPD Flow Restrictor with Quick Fittings. the RO/DI unit i got has the 75 GPD Flow Restrictor on it should i up grade it to the 100 GPD Flow Restrictor?

  • Julie says:

    I bought the upgrade after I went from a 65 gal to a 180 gal and I couldn’t be happier. It is well worth the money. Mark you have me thinking now about a third upgrade now. I have the psi to support it. Hmmm

  • Great video as usual Mark! Informative and useful!

  • Thierry says:

    Hey Mark,

    Great tip; as you know I am from belgium so buying at BRS isn’t an options … I have ro/di unit installed and I could buy a second membrane as you say (since I allreadu have a booster pump this shouldn’t be a problem); but my other question about this … i am using some kinda onion filter to get 0 tds … IF i still have that one at the end (after the membranes) will this restrict the clean water I get?

  • Darren Crownover says:

    A tip for the waste water, I have my RODI unit set up in my laundry utility room. I run the waste water line right into my clothes washer. I use the waste water to fill the washer (I keep an eye on it and use a timer to avoid the opps it overfilled flood) and clean my clothes with the waste water.

    This helps from putting too much pressure on my septic system by preventing it from filling with clean useable water.

  • Nick Sevier says:

    Great tip mark! Can you actually drink it though? I heard it was bad for you.

  • Jeffrey Peterson says:

    I heard that drinking RO/DI water will rot your teeth out, do to it not having any fluoride, is that true?
    Thanks, Jeff

  • Taiyab Patel says:

    thanks Mark. great tip. going to try it soon. If you dont mind me asking, whats the music at the end of the video called?

  • Brian Davis says:

    Cool tip Mark! This has been On my to do list and I’ll be ordering a shut off valve for sure before I upgrade! (:

    Lol, you have to wear a mask to get down to that sand bed?! (; and how’s the rimless working out for ya? Tank looks great.


  • Frankie says:

    Hi, Mark

    Great tip, I thought you aren’t suppose to drink DI water? I know RO is ok but thought the DI portion is bad for you?

  • Reefstinger says:

    Great video mark , always on top of things. I send my waste water to my koi pond in my back yard , during the hot summers and water evaporates, The rodi refills the pond. never thought about an upgrade. But this sure makes since in case of emergencies .

  • Mark thanks for that tip I’m calling 1st thing in the morning to order a 2nd membrane for my R/O system that should saved me a lot of time and a lot of waste. Keep up the tips we all benefit from them thanks again.

  • tim says:

    I may have to get the kit but i use bladder storage tanks with a permeate pump this cuts waste already about two gallons waste to one gallon pure. Do not drink rodi water it is bad for you. ro is good rodi is bad it will deplete needed minerals in your body, It won’t just not supply you with minerals it will remove minerals.

  • Kevin says:

    Drinking DI water isn’t a good idea. Due to the purity of the water and the lack of minerals and electrolytes, DI water can actually do more harm than good (one glass won’t hurt, but drinking DI water over time could cause an electrolytes imbalance). Put a T before the DI filter and drink the RO water.

  • The threat of DI water causing bodily harm is small. The issue comes if you drink A LOT of it ALL the time. Then the purity of the water can become an issue. I’ll use DI water to make tea which puts minerals and other things back into the water.

  • Reefstinger…that’s a GREAT excuse to get a big fish tank! “Honey…if I get a 1000 reef gallon tank, then I can fill the 4000 gallon poi pond with JUST the waste water from the reef tank!!!”

  • Brian…rimless is working out great till my female bluethroat jumped out today. 🙁

  • Taiyab…it is music by a guy named John Bohlinger. Song is unnamed.

  • Theirry…what is an onion filter?

  • Mark H. says:

    Great tip Mark, tank is looking better with each video.
    Can wait untill the tank update video 🙂

  • Julie…if you add another membrane let me know how it goes!

  • Mark H. says:

    Mark, is she ok?

  • Mark…tank sitter found her dry as a bone. She didn’t make it. Sad day.

  • Mark H. says:

    Sorry to hear that, why is it that you finally get a pair of something and one decides to bail?

  • Mark…I’ll never know why she jumped. Maybe fish aggression, maybe something spooked her.

  • Jesse says:

    One caveat of the 150 GPD upgrade is you MUST have a steady 60PSI in order for it to work properly. Also, in a pinch, you can bypass your RO membrane and run the water from your sediment/carbon filters right into your DI resin. Yes, it burns up your resin a lot quicker, but if you have to make 60 gallons of water in an emergency situation, that is the quickest way.

  • Dave From Brooklyn says:

    That is a great upgrade but how does it affect your resin usage. You’d think it would excelerate its life cycle.

  • Dave says:

    Nice tip, but where I live the water is pretty expensive, so the least amount of waste water is preferred. I went with a straight DI medical grade system with one DI canister and one carbon canister . There is no waste water with a 100% useability. The canisters last 6 to 8 months for about $230.00. Seems like alot but considering the amount that I use at any given time, and the cost of the water in the first place, it works out OK. Absolutely no problems as of yet……

  • Brian Davis says:

    Mark…Dang! That really sucks big time about your Trigger! ): did you receive that email I sent out earlier this month regarding jumpers?


    I think I’m about to prophylacticly change out my filters and membrane. I’ve been making water for 20 months now with hardly any change in my DI resin and my filters are doing amazingly well. The water here in Albany where i am is ridiculously clean (; I’m really interested in a second membrane.

    Anybody else get this much life outta their filters and resin? Seems like I’m long overdue, but my product water after it’s filtered is great and I’m storing both mixed and unmixed brutes with water ready to go. They’re rotated out about two weeks via water changes. Hmm.


  • Swiss Chris says:

    Great tip Marc, i will order one right away.

    Just one thing, i think you have not spoken about it but there is a membrane flush kit installed as well right ?

    Kind regards

  • paco says:

    Awesome video i been waiting for something like this. Im getting a second membrane. Thanks mark keepit up!!!!

  • Hi Mark,
    Love the RO/DI video that came at the right time because I’m looking at that same unit and 150 kit. And it was like you were reading my mind when you started talking about adding a third unit.

    But wouldn’t the unit make even more good water if the units are connected in parallel instead of in series? I understand that it would produced more waist water.

  • theplummer says:

    Great tip. I too was worried about the waste water, as water in my particular community is VERY expensive, not to mention that I also get charged for sewer use based on the amount of fresh water purchased.

    Therefore, I found a unit made by WATTS Premier. It’s a zero waste retrofit pump. It returns your waste back into the hot side of your water lines. This makes sense to me. This way, If you don’t have a back flow preventer on your entry main, your meter will run backwards, therefore no charge for waste water or sewer charge. The waste water gets pushed into your water heater, and you shower and do laundry with that water, meanwhile your RODI gets untreated water every time.

  • John M says:

    I did the upgrade and work well. You do not have to change your Flow Restrictor. If you have 75 unit keep it for 75 if you have 50 units keep the flow restrictor for 50. You need to keep the same flow. If you put them in parallel you are not changing anything put getting more output and more waste 2 times that is why waste from no. 1 goes into no. 2 to reuse the water and take more out. As Mark said I have a well and I needed a booster pump and that cut time and water waste too.

  • Francesco says:

    Hi Mark,

    great tip especially in times where water becomes more precious and wasting it hurts the heart , but a couple of questions/doubts come in mind:

    -the waste water is much more “dirt” than the incoming water. Will not the 2nd membrane loose effectiveness much faster?
    In Wikipedia under “Disadvantages” is reported:
    “Household reverse osmosis units use a lot of water because they have low back pressure. As a result, they recover only 5 to 15 percent of the water entering the system. The remainder is discharged as waste water. Because waste water carries with it the rejected contaminants, methods to recover this water are not practical for household systems.”

    – the “second” water is as good as the “first” or will it deteriorate the first?

  • Robert Smyth says:

    Hi Mark,

    One other questions about the RO/DI unit, by connection the waist water line to the second unit, will the second unit product the same quality water? I was wondering because the waist water it is being fed I assume it is somehow more contaminated the the original water that is feeding the first unit?

  • eric says:

    Mark someday could you talk about cloromine filters? Some say its nessisary others say its BS what gives?

  • Jason Reynolds says:

    I have a whole house water filter system. I run that through my RO/DI unit so my tank water is pretty awesome.

  • Earl says:

    Mark, tank looks great. I have been using an API Tap Water Filter that I got from Marine Depot. I have been using this for about a year and a half. I haven’t had any problems, the tank is healthy and fish and corals seem happy. Do you know anything about these? I replace the cartridges just as the cartridge starts to turn color, sometimes before. Fortunately, we have great water to start with here in Washington State, which I think is important to start with.

  • Matt says:

    Does a system like this make sense for a 65gal with 20gal refugium? If not, what would you recommend as the best overall value?

  • John m says:

    the “second” water is as good as the “first” or will it deteriorate the first?
    yes, Good as the first.
    -the waste water is much more “dirt” than the incoming water. Will not the 2nd membrane loose effectiveness much faster?
    no, It will be the same I was told. So I check it with my meter that BRS sells and it at the same level.
    membrane flush kit installed as well right? Yes you need one to clean the membranes out for dirt and rust that gets in there.

  • Gordon says:

    Hey Mark,

    Sorry to hear about your blue-throat 🙁

    Time to put a nice looking frame with netting–sounds like another good show idea. . . 😉

    Thanks again,


  • Gordon..mesh will be the temporary fix. I’m going to get a canopy made.

  • Hi Mark,

    I remember when I was very young my G-dad did fresh water and I remember he had allot of issues with the little red tail sharks jumping out of the tank. We often found them on the floor.

  • Earl says:

    My son has a laser and he made custom fitting acrylic tops that have 1/4″ holes arranged in a staggered pattern for ventilation. They are pretty cool. The top is solid under the light fixture, the holes cover the rest of the tank.

  • Swiss Chris..yes there is a flush kit installed on my unit. It is a separate purchase from the 150 gpd upgrade though.

  • Mike McVay says:

    Hi Mark,
    I took your advise and ordered the 150 gal a day upgrade for my RO/DI unit from BRS. What an improvement! I have a 125 gal tank and it took only a couple of hours to get 30 gals for my water change! The $85 dollar investment is well worth it! Thanks for the tip.

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