RO Unit for FW

Discussion in 'Aquarium Water' started by Dom90, Aug 11, 2015.

  1. Dom90Fishlore VIPMember

    I know RO/DI units are a must for SW so you don't introduce extra nutrients to the aquarium and prevent algae problems. But what I want to know is are they effective for FW? I'm thinking if my tap water is high in GH/KH, it may be introducing unnecessary nutrients. I been getting algae outbreaks lately and I even reduced lighting from 10 to 8 hours and haven't used Flourish comp for two weeks now. My phosphate test shows I only have 0.25-0.5 ppm.

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  2. LiterallyHydroWell Known MemberMember

    My only gripe with using an RO/DI unit in freshwater aquaria is you must use something like Seachem Replenish during water changes. If you aren't using Replenish you're removing a lot of the trace elements that the fish require.

    The reason this isn't necessary in saltwater aquaria is because the salt mix usually contains the trace elements the fish need.

  3. AkiliValued MemberMember

    Using an R.O. unit will provide water without General Hardness (GH) or Carbonate Hardness (KH).I use 50/50 it works out very well for me.Keep in mind that With 99% of plants RO isn't needed.
  4. Dom90Fishlore VIPMember

    But if my tank is heavily planted and adding the Replenish, the nutrients added will be used by the plants instead of feeding the algae so in theory a RO unit should be another way to minimize the amount of nutrients used by the algae right?

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  5. BDpupsWell Known MemberMember

    I would not consider your tank to be heavily planted. A better solution would be to figure out what is going on and why you have algae. There is an imbalance of something. Lighting, ferts, or CO2. I would add more plants, and reduce the lighting more before buying a RO unit or RO water. Having a plant substrate plus adding ferts to what is more of a low light set up is probably a big contribution to the algae. Cut off any leaves of the plants with algae. The only thing I would dose with is Excel. And even with that I would use it sparingly.
  6. BigXorValued MemberMember

    What do you mean by using Excel sparingly? (use less everyday or full dose occasionally)
  7. BDpupsWell Known MemberMember

    Full dose occasionally IMO. Since the OP is not injecting CO2, reducing the lights and ferts is where I would start to figure out the algae problem. Excel can be used to help eliminate algae. So maybe using it occasionally is not good advice. But that is what I would do. I would also get more plants to help use whatever nutrients the algae is using in the hopes of the plants out competing it.

    EDIT: Using RO water may very well help the algae problem. But it seems to be a bit of a extreme solution to me at this point.
  8. junebugFishlore LegendMember

    You probably just need to start dosing carbon... Most algae outbreaks are nothing to do with the tap water used, and have more to do with lighting and cO2 imbalances. Obviously excess nitrates from overstocking/not enough water changes can cause issues as well, but I'm assuming your tank is stocked correctly and that you perform good maintenance.
  9. Dom90Fishlore VIPMember

    Yea I actually think my stocking is a little on the light side. I am already dosing Excel five times a week. Water changes are done every other week as my nitrates are rising only about 15 ppm a week. I will cut down lighting a bit more to see if that helps. Would getting injected co2 actually help my situation?

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  10. BDpupsWell Known MemberMember

    You can also try raising the light up a bit higher.
  11. Dom90Fishlore VIPMember

    What do you mean? Actual height from tank floor?

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  12. BDpupsWell Known MemberMember


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