RO and TDS Questions

Discussion in 'Reef Chemistry' started by Marc, Mar 10, 2014.

  1. Marc

    Marc Guest

    Ive got access to RO water thats being produced at 2-3ppm. Would you guys find this acceptable for mixing with salt? I have RO/DI water at home that I use for top offs thats reading 0 ppm and I'll continue to use that.

    But at my shop our RO machine is just way more efficient. Its dumping 1 gal for every 3 gals it makes.

  2. Coral reefer

    Coral reefer President

    So you are goons take it home? Could maybe run it through a DI at home? 2-3 should work well IMO.
  3. sfsuphysics

    sfsuphysics Supporting Member

    2-3 is nothing and I'd feel more than comfortable with that. The upside is if you did run that through a DI unit, you wouldn't go through resin very fast :)

    THat said it depends how much water you need to bring home, for me it would be too large to be feasible. I recall getting into the hobby and hearing about how in San Diego Scripps had a faucet at the end of a pier where you could get natural salt water (not sure if it was filtered at all), people asked if Steinhart was going to do something like that too, etc. For me I wouldn't use it because I'd need too much of it. Now if you're bringing home a 5g jug every couple of weeks sure, but if you need 50g for a water change.. no way :D
  4. Marc

    Marc Guest

    I'm sometimes lazy and rather use my water at home for WCs but I hate wasting resources like water especially during a drought. I probably wont hook it up to a DI filter because its going to cost me more money, more equipment and more space. I would keep using the DI water for top offs though.

    How high would you be comfortable letting your TDS go up? or whats still acceptable, in your opinion of course?
    I probably use 5-10 gals a week at the moment. So I figure it wouldnt be that bad...
  5. sfsuphysics

    sfsuphysics Supporting Member

    I might not be the best one to comment on this as I'm currently dealing with some water quality issues that I think is stemming from my RO unit but... ;)

    Acceptable for me, would probably be anywhere 5-15 ppm, kind of hard to say as I always run through DI resin for one last cleanup. It's important to note that you're not really measuring one particular atom/element in the water whatever these "solids" are, but instead of are measuring free ions (try to measure your reef tank with lots of free ions, your TDS meter will max out), so who knows what exactly is causing readings on your TDS meter.

    That said I've always been of the mindset that the tank (feeding, pooping, etc) will make the water WAY dirtier than the water you put into it, some people like to start with a clean slate when they do it, I don't feel like trying to squeeze those last few PPM out of your fresh water will make that much of a difference in the long run. Now if your putting in water straight from the tap with some chloramine absorbing thing in it and your TDS is north of 100 you might run into issues... might, you could also have no problems if everything in your tank is in a nice sync with one another, just enough algae to consume whatever nasties are in the water, and just enough larger critters to consume the algae that's eating the nasties, etc.
  6. Marc

    Marc Guest

    Okay this sounds reassuring. I'll give it a try.

    If there are negative effects - what would I see? algae bloom? dying coral?
  7. sfsuphysics

    sfsuphysics Supporting Member

    going through prefilters and RO will take out most of the "nasty" stuff that would kill off corals instantly. More likely than not you'll see algae/diatom growing faster on the glass.
  8. Coral reefer

    Coral reefer President

    I think I've coralated cyano outbreak with spent DI. Could be just in my head tho.

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