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Ideal additive for RO/DI water for freshwater

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  • Ideal additive for RO/DI water for freshwater

    Hi,
    My L.A. County tapwater is very hard (8dKH, 12dGH), alkaline (pH=8++), has recently been turning in about 20ppm of Nitrates and God knows how much of phosphates and silicates. With fishload, even with a planted tank, I'm hard pressed to maintain 40ppm of NO3 (API test), so my shrimp (especially cherry shrimp) are not breeding and not even surviving too well. So I'm thinking of getting RO+DI water. However, now I'm in new territory with confusing information from different sources. Could somebody please help me select the ideal additives for weekly 40-50% water change RODI water?

    Here are the details:
    Size 80g, 60g water column, planted
    Stock: 6 Zebra/Leopard danios, 10 Rummynose Tetras, 10 Green Neon Tetras, 6 galaxy rasboras, 2 dwarf powder blue gouramis, 5 Otocinclus, 1 Stardust Plecostomus, 10 amano shrimp, 10 red cherry shrimp, 10 yellow shrimp, countless (>30?) Assassin snails.
    Plants: Swords, Cryptocorine, Bacopa, Cabomba (not doing very well), Red Ludwigia, Glossostigma (not doing very well), tears,

    Current tap-water based water parameters (all API tests):
    dKH=8; dGH=12; pH=8.2 before CO2 injection; pH=6.6 with CO2 injection during daytime; Dosing mostly with Potassium Sulphate and chelated Iron.

    Trying to change to: RO+DI.

    Any advice will be appreciated. I would especially like to know what combination of Seachem Equilibrium or anything else I should routinely add to my RODI water to maintain optimal buffer and oiptiomal Ca + Mg etc. By the way, what is the optimal level of KH, GH, Fe (chelated) etc. I should shoot for?

  • #2
    Re: Ideal additive for RO/DI water for freshwater

    Oh, forgot to add:
    I also have Windelov Fern, Java fern, Fissidens moss, and floating fast-gowing pennywort to provide shade to the Windelovs and try to take out some nitrates.. Dark black wood decorations, don't know exactly what kind of wood.

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    • #3
      Re: Ideal additive for RO/DI water for freshwater

      Thanks for the post!

      When using RO water, it is critical that you add back the minerals that are stripped during the filtration process. To do this, you have two options:

      Equilibrium
      http://www.seachem.com/Products/product_pages/Equilibrium.html

      aquavitro mineralize
      http://www.aquavitro.com/products/mineralize.html

      The first time you add either of these products, you will add it to your aquarium for the entire volume and dose it in order to target your desired GH. For a planted aquarium, we recommend between 3-6dh or 50-100ppm. Once you have set the hardness in your aquarium, you will only need to add it to your replacement RO water each week to get it to the exact hardness of your aquarium.

      For buffering the pH in RO water, we recommend using our Acid and Alkaline Buffers, which are ideal for planted aquariums because they are carbonate based buffers. They should be used in conjunction with one another according to the ratios in order to target a specific pH. I would try to maintain a KH level between 2-5dkh. To read further about these buffers, follow the links below:

      http://www.seachem.com/Products/product_pages/AcidBuffer.html
      http://www.seachem.com/Products/product_pages/AlkalineBuffer.html

      I hope this helps!

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      • #4
        Re: Ideal additive for RO/DI water for freshwater

        Originally posted by Tech Support AN View Post
        ....

        I would try to maintain a KH level between 2-5dkh. To read further about these buffers, follow the links below:
        ...

        I hope this helps!
        Yes, it is very helpful, thank you very much. Just a quick follow-up, though. Even though I am injecting CO2, and bringing pH down by 1.0 (say from 7.0 to 6.0) during the daytime due to the CO2, would a carbonate hardness of 2-5 dKH still be appropriate? Doesn't that leave very little room for safety against NO3 formation, etc., or am I not understanding water chemistry completely? [I am an accountant by profession! :)]

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        • #5
          Re: Ideal additive for RO/DI water for freshwater

          It is the carbonate hardness that will keep your pH stable. A carbonate hardness of 2-5 dKH will be sufficient to maintain your pH.
          The formation of ammonia, nitrites and nitrates is a separate matter. Waste being produced in your tank will convert into ammonia, nitrates and nitrates. It is your beneficial bacteria (the biofilter) that ultimately consumes these nitrogenous products. A tank with the proper filtration should have zero ammonia and nitrites and 20 ppm or less of nitrates.

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          • #6
            Re: Ideal additive for RO/DI water for freshwater

            Hi,

            Thank you for your reply.

            I understand what you say, but I seem to have not communicated my question/doubt very well.

            Of course NH3/NH4 and NO2 are converted by bacteria, but isn't it the case that NO3 cannot be converted that easily by bacteria and ends up forming nitric acid (HNO3) for which you need a carbonate buffer? So my question was, I am adding further stress by CO2 injection effectively lowering pH by 1.0 during the daytime (which I believe is roughly consistent with 30-40ppm of CO2 if you look across the pH-kH-CO2 charts for any value of kH)?

            Given all the above, I was asking, what was a good, safe, minimum kH to maintain in my tank.

            Thanks so much,
            a

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            • #7
              Re: Ideal additive for RO/DI water for freshwater

              I'm sorry that we have not answered your questions clearly.

              How quickly your NO3 is converted to nitrogen gas depends on the types of anaerobic bacteria you have in your biological filtration. To be honest, if it is a species that is specifically designed to function in an aquarium environment, and you have plenty of media supporting the bacteria, than it should convert it rather quickly and not form nitric acid. I'm guessing you are referring to carbon dosing? If you were to use our beneficial bacteria, Stability, it does not require a carbon source to function properly and will convert ammonia, nitrite, and nitrate very quickly.

              With your CO2 system, do you have a pH monitor that will help to control the injection rate, thus helping to control pH fluctuations? This is really the best option when using CO2 systems, in order to control the pH. As for the KH in a planted aquarium, we generally recommend 2-5dKH. I personally keep a very low KH in my planted aquarium because I use RO water, and I do not have any issues with pH fluctuations.

              I hope this helps and if you still need assistance, please let us know.

              Comment


              • #8
                Re: Ideal additive for RO/DI water for freshwater

                Thanks! That is reassuring.

                Yes, I do have a Milwaukee pH controller. I've set the pH on this at 6.6-6.7, and it sits in front of a timer which shuts off the CO2 at night. So I really have pH going from 6.7 (day) to 7.0-ish (overnight into early morning).

                The reason I chose 6.6-6.7 is the following: (1) The degassed pH of my tank water is about 8.2, so lowering the pH to this level with CO2 provides about 40ppm of CO2; and (2) most of the fish I have (tetras, otocinclus, shrimp, danios, rasborras, gouramis) are reputed to do west in neytral-to-slightly acidic water, unless I'm mistaken.

                THe problem I have been having :(1) Cherry shrimps not doing very well; (2) Plants, especially stem plants like cabomba are rotting, and colorful plants with bright red leaves are turning green. Light and ferts are adequates, I think, as detailed earlier in this thread, but nitrates are a bit high and dGH is high (at 12). That's why I'm moving to RO/DI water.

                Any further suggestions will be gratefully appreciated.
                Last edited by aadro; 04-04-2013, 13:03. Reason: afterthought/adition

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                • #9
                  Re: Ideal additive for RO/DI water for freshwater

                  This is an addendum to my above post, as I forgot to address this part from your email:

                  Originally posted by Tech Support AN View Post
                  I'm sorry that we have not answered your questions clearly.

                  ... I'm guessing you are referring to carbon dosing? If you were to use our beneficial bacteria, Stability, it does not require a carbon source to function properly and will convert ammonia, nitrite, and nitrate very quickly.
                  ...

                  I hope this helps and if you still need assistance, please let us know.

                  Yes, I use Stability with every water change at recommended dosage, and I also use quite a quantity of Seachem Matrix (about 250mg) in addition to standard Fluval biomedia cylinders in a Fluval 406 canister filter. Further, I have two Aquaclear Powerfilter Quickfilters (like this: http://www.wag.com/fish/p/aquaclear-quick-filter-powerhead-attachment-for-all-aquaclear-powerheads-220997?site=CA&utm_source=Google&utm_medium=cpc_W& utm_term=HAG-1172&utm_campaign=GooglePLA&CAWELAID=1323852201&ut m_content=pla&ca_sku=HAG-1172&ca_gpa=pla&ca_kw={keyword} ) wherein I have placed Matrix inside the cylinder of these two filters behind the polishing pads, about another 250mg. Of course, the Fluval has it's own media as well, and the size of the filter (plus the two Quickfilters) is I believe adequate to my 80g tank.

                  But I can't seem to get rid of nitrates, whatever I do. One reason might be that my tapwater already has 20ppm NO3. That (and the hardwater and possible other unmeasured contaminants) are reasons for my deciding to go to RO/DI.

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