Recycled R/O water has anyone re run it again.

Discussion in 'Equipment' started by POOLSCAPES, Mar 16, 2015.



    I am concerned about the drought. I am currently running over 500 gallons approx. I am trying to figure is there a way to recycle the water throught the R/O system again. This might be bad idea? I am thinking of catching it in a water tote and plumbing it in my irrigation system. Seem to me the waste water would be cleaner than the city water that is coming in to my house. Please can I get some ideas. I have a spectrum maximum 5 cartridge. Thanks
  2. Enderturtle

    Enderturtle Volunteer

    You could put your waste water into a rain barrel and then use it to water your plants, clean your car, anything really.

    Do you have a water saver rodi unit? i.e. two RO membranes on one rodi unit
  3. aqua-nut

    aqua-nut Supporting Member

    Another water saving tip...

    Make sure your pre-filters are good and you have enough pressure. As pressure drops the ratio of waste to product goes up!

    I use my waste water to fill the pond. My goldfish are tough and a bit higher TDS is no big deal.
  4. sfsuphysics

    sfsuphysics Supporting Member

    +1 on 2 membranes, that will cut your waste water in half. Assuming you have appropriate pressure (I have a booster pump since my pressure is a low 40PSI)
  5. HiFidelity

    HiFidelity Guest

    Running your waste water back through the RO/DI is a good way to kill your cartridges/membrane etc. quickly... As recommended by others reusing your waste water on plants, etc. and running 2 membranes is a good way to conserve.

    I filter drinking water through my RO/DI as well so I'm always making freshwater and every now & then think I should try to make my system more efficient. For a while I thought about collecting rainwater and running it through RO/DI but where's the rain? haha
  6. Just don't water your plants with saltwater, obvis. ;)
  7. Coral reefer

    Coral reefer President

    As people said. Run multiple membranes in series. Waste from one to input of next. I run three. Basically 1.5:1 waste to product that way.
  8. sfsuphysics

    sfsuphysics Supporting Member

    Damn how big of a booster pump do you have to run 3 membranes, I can't imagine you have stronger water pressure higher on the hill than me.
  9. Coral reefer

    Coral reefer President

    I'm at 38 ish normally. I run the brs booster pump. Gets up to 60 psi when everything is clean.
  10. neuro

    neuro Webmaster

    I did not know this...
  11. BAYMAC

    BAYMAC Guest

    FWIW temp is also a determining point for waste:production ratio. Some people wrap their feed line around their water heater.
  12. Coral reefer

    Coral reefer President

    I have looked around for bigger booster pumps, but I am not sure they are made for our type systems, or else I am not looking in the right places. I'd love to find one that could boost up even higher with all three membranes.
  13. Coral reefer

    Coral reefer President

    I take it warmer is better. Do you know if there is an optimal temp? Or what would be too hot? I've played around with feeding with a mix of hot and cold water, but the temp fluctuates as water is used in other parts of the house.
  14. Enderturtle

    Enderturtle Volunteer

    Be careful with hot water.

    Too hot = dead filters

    Lets say you have it on Warm.

    If the cold water is used up elsewhere in the house (laundry, cold showers, etc), you might be running very hot water through your rodi, even if you had it on warm setting.
  15. Coral reefer

    Coral reefer President

    Basically what I said, but what optimal, and what is too hot?
  16. Reef Nutrition

    Reef Nutrition Sponsor

    IIRC you want around 70f... IE room temp, not ground temp most our tap is delivered at. Don't feed it from your hot water, just wrap the feed line around the hot water heater.
  17. Reef Nutrition

    Reef Nutrition Sponsor

    Oh they do, in fact, I just saw one that IIRC was 2x the size as the powered booster pump we're used to as the max size. I'll try to find out where they got it.
  18. Coral reefer

    Coral reefer President

    Too much gunk coming outta the water heater? Makes sense.
  19. Reef Nutrition

    Reef Nutrition Sponsor

    that (build up in hot water heater), and the other fact you mentioned (can get too hot if something else was turned on)
  20. sfsuphysics

    sfsuphysics Supporting Member

    Membranes are typically rated at 77°F and 60PSI, I read somewhere that lots of work was done in SoCal and because they have warmer water from the pipes, that's the "standard" that was applied to membranes today.

    The temperature can cause some fairly large differences too, Assume you have a 100GPD filter, and 60PSI, if your water is 60°F then you'll only produce about 70GPD, if it's 70° then you'll make about 87GPD, if it's 80°F then you'll make about 105GPD.

    Upper limit is somewhere in the 90's as far as damaging your membrane, so if you keep it in the 80 range you're good to go.

    To increase the temperature you could buy a couple hundred feet of vinyl tubing and toss it in your sump to get warmer water, but you'll be paying for that increased production with electricity to re-warm your tank water up (however if it's a hot day and your tank is in the 'overheating" mode you could come out ahead). But the reality is unless you have something you submerge your tube into you're not going to get much out of it, even with a few hundred feet of tubing water moves too quickly to allow ambient air temperature to warm it up an appreciable amount. That said, you could throw it in a bucket of water that's sitting outside in the Sun.

    However before you go getting too crazy about trying to improve the output, you should probably see where you stand as far as temperature :)

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