Click for Westport Click for Nordhavn Click for Abeking Click for Llebroc Click for Lurssen

RO Sand Filter

Discussion in 'Watermakers' started by Capt Ralph, Mar 8, 2022.

  1. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    11,023
    Location:
    Satsuma, FL
    We have been requested to investigate a sand filter for a 500GPD RO system. Near coastal FL still loads up the standard skinny cartridge 30m pre-filters. I was about to install a Big Blue cartridge filter until this request came in.
    Been dragging my feet but this week, I have to present a plan.
    Any sand filter users out there? Anybody thought about this?
    Oh also, under a cockpit deck, Max vertical is 34"
  2. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    7,341
    Location:
    Miami, FL
    I know they re on option on some systems incl sea recovery but never used them. Check the sea recovery website to see what size they are. If I m not mistaken it complicates the plumbing as they need to be back flushed. Happy with the commercial size ore filters :) KISS
  3. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    11,023
    Location:
    Satsuma, FL
    Ore filters? Just found some notes on this. Reads of intrest. I'll dig deeper when I'm back at my desk computer. Can't do much on a small phone.
    Thx
    Last edited: Mar 8, 2022
  4. Ken Bracewell

    Ken Bracewell Senior Member

    Joined:
    Feb 9, 2006
    Messages:
    1,624
    Location:
    Somewhere Sunny
    They work well. I had them on RENA.
  5. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    11,023
    Location:
    Satsuma, FL
    Anybody have a mfg name, model number, brand?
    The searecovery dot org has parts per RO model. No filter page found.
  6. BRyachts

    BRyachts Member

    Joined:
    Mar 31, 2006
    Messages:
    115
    Location:
    Ft Lauderdale
    I've used them on some boats I've worked on, and they've been fine. Other models of watermakers did not use them. Six of one, half dozen of the other.

    Size, make and model will be up to your needs and size limitations. And yes, back flushing plumbing is required, but PVC works. You'll probably have to shop the independent dealers, WaterMakers Inc, Watermakers of So Fla etc etc.

    For your convenience though, I do like the Big Blues in either single or double stack height, again depending on your size needs. But, BUT, buy the models that use bag filters, NOT pleated filters. The internal flow is opposite. Bag filters are readily available and MUCH easier to store than pleated filters. And often they can be rinsed and reused, within reason.

    Also consider, if you don't have already, a charcoal filter on your system flush. This will help neutralize the chlorine in city water when flushing, and extend the life of your membranes.
  7. ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    668
    Location:
    Chesapeake Bay, USA
    We use Big Blue. Not with RO, just mostly because our source is usually well water, not treated city water.

    The filter elements we use (for both home well and on boat) are not pleated. DGD-2501 duel gradient 25 micron/1 micron.

    Bag filter?

    -Chris
  8. BRyachts

    BRyachts Member

    Joined:
    Mar 31, 2006
    Messages:
    115
    Location:
    Ft Lauderdale
    Come in all common sizes. Store MUCH easier.

    Again, internal flow is opposite of a pleated/spun filter. So either buy appropriate inlet/outlet filter head, or, in a pinch, I've just spun the filter head 180, ignore the directional arrows, which reversed the water flow.

    A pleated/spun filter flows from outer to inner, a bag filter flows from the inner (bag) to the outer. All sediment is captured in the bag.

    https://www.mscdirect.com/browse/tn...a79f389fd46a12f000395ab760cd3b48&gclsrc=3p.ds
  9. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    11,023
    Location:
    Satsuma, FL
    We have a bag filter on hand but it's to tall to fit under the cockpit deck.
    However, it has an inlet on the top and outlet on the bottom, as expected with a bag.
    How does a bag filter install in a cartridge filter designed assembly?
    Last edited: Mar 9, 2022
  10. ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    668
    Location:
    Chesapeake Bay, USA
    Thanks. Interesting, hadn't seen those before.

    -Chris
  11. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    11,023
    Location:
    Satsuma, FL
    Still looking for a final filter but I have to install some (improvement attempt) interim filter this weekend.
    Currently a 10" x 2.5" 30m filter has been clogging up (per the owner) quickly.

    In my inventory I have a dual (parallel) HRO dual 10" x 2.5" and a single 10" x 4.5" filter set ups.

    Tech filter question for you kids;
    What set up would last longer in near FL coastal water?

    I am not excited about the filters that require back washing for this topics system.
    Last edited: Mar 10, 2022
  12. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    11,023
    Location:
    Satsuma, FL
    Another question; I wonder if I can mount a to-tall sock filter other than vertical?
  13. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    7,341
    Location:
    Miami, FL
    The bigger filters, sometimes called commercial, last a lot longer. In the Exumas we get 150 hours out of them. Obviously I make sure the water maker is off before maneuvering in shallow water …. Simple. Way to go in my opinion