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Starting new South American Tank. Need to lock in 6.5ph (Buffer help please)

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  • Starting new South American Tank. Need to lock in 6.5ph (Buffer help please)

    PH: 7.7
    KH: 8dkh
    GH: 10
    PPM: 156
    RO/DI (Aquatic store bought)
    PH: 6.5
    KH: <1 to 1
    GH: <1 to 1
    PPM: 0
    Mixed 50% in container
    PH: 7.4 - 7.5
    KH: 4dkh
    GH: 5
    PPM: 78
    • I really want to use your 2 buffer products but I keep seeing PH swing horror stories. I just want a 6.4 to 6.5 PH to have thriving German Blue Rams, Cardinal Tetras, and Amazonian plants. Please help me figure out how to buffer this tank before planting and setting up tomorrow. I want to prove to everyone that buffers are safe to use so use me to preach for you guys and gals! Help!

  • #2
    Oh and yes I will be running CO2 for the first time.


    • #3
      Good day Aquaticluptionian,

      Thank you for your question. When adding CO2 it's important to know that it creates carbonic acid and will act as the acidifier in your system. As a plant enthusiast myself I prefer using Alkaline buffer to bring the alkalinity up to where I want it, typically 4dKH, for tropical soft water fish like those you want. I highly recommend waiting until you've found out how much CO2 you will need to add to reach your 6.5 target pH prior to adding fish; planting from day 1 is also recommended. When starting a new tank with CO2 I prefer to wait at least a week after planting and starting CO2 so I can monitor pH to ensure it's stable and not overdoing the CO2. Will you be using a solenoid to run CO2 on a set schedule or will it be going 24/7?

      Since you'll be using RO/DI water it's essential to remineralize it. I've been using Equilibrium for decades to both achieve a target GH and provide the essential plant nutrients it's made of (Ca, Mg, K, Fe, and Mn). Keep in mind that GH boosters and alkalinity buffers are made from things that are plant nutrients so your plants will be taking them up, making it important to monitor GH and KH to figure out how much you will need to add throughout the week to maintain the desired levels of both.

      That's a nice aquascape! As an aside, the wood you're using is going to float when you add water so be sure to weigh it down before water goes in.

      If you have further questions, please don't hesitate to reply here.

      Kind regards,


      • #4
        Yes my sample cup of the 50/50 mix of RoDI/Tap KH is 4kdh and dropped to 3kdh 12 hours later. The GH is still 5gdh. So realistically I shouldn't add equilibrium right? I mean if I raise GH it will raise KH right? Plus those numbers look good for shrimp and cardinal tetras before adding minerals correct? Yes, I'm not sure how the PH is at 7.4-7.5 with it's low end hardness. I definetly have been reading to keep KH at 5 so that I dont have PH swings. I guess that's what the Alkaline Buffer will be good for. I definetly will take your advice on the CO2 before fish. I just want to reach my parameters and lock them in so all I have a steady regimen. Yes, I have an auto shutoff solenoid and will run it on a timer.
        Since Im using only half RO/DI water is it still essential to remineralize since the tap brings it to its semi sweet area of GH and KH. Also I keep getting different GH recommendations for shrimp, what do you think?

        Thanks so much about the complement. Id like to enter some contest and just have a beautiful show tank with minimal issues. The driftwood luckily is on 2 slate sheet rock to hold both down! Thanks a lot for the reply. I hope my response helps you to continue to help me and many others. I think we are covering a strong topic in the community and if we can make it clear for others then people will stop being afraid of using the buffers in conjunction. I plan on updating parameters when I get this thing going.

        Just need to understand the KH GH PH correlation. I cant phathom how KH 3, GH 4, could even be a PH of 7.5
        Last edited by Aquaticluptonian; 04-10-2020, 20:28.


        • #5
          So the tank is up with just a bit of mini dwarf hairgrass. CO2 is reading green. 1 to 2 bubbles per second. Ultum Contrasoil.
          Tank Parameters
          50% RO/DI, 50%Tap
          PH: 5.9 using PH meter stick
          KH: 2
          GH: 3
          TDS: 93
          Ammonia: .25 (possibly from aquasoil)
          Nitrites: 0
          * Following Seachem New Tank solutions with Prime and stability - The goal is 6.5 PH with 4 to 5 KH and 5 to 7 GH. I'm on day 2 but should I just do no water changes or add an alkaline buffer? Is it true that I adding KH is pointless because the buffering of aquasoil will keep eating it? Just want this done right. This coming week I get the rest of my plants. I will be dosing with a fertilizer with no nitrogen or phosphate to avoid algae bloom.
          *Running lights 6 hours for a week to also avoid algae.
          *Should I maybe just do a water change with 60% Tap and 40% RO/DI to increase hardness instead of buffers? I have equilibrium just in case I need to raise GH.
          * Is it true that when raising KH by 1 point that it can up your PH by one whole point? Let me know as I'm using mostly your products. Waiting to add purigen after tank cycles.


          • #6
            Hello Aquaticluptonian,

            Thank you for the additional information; there's a lot to unpack here.

            1- GH and KH: General Hardness (GH) is a measure of the divalent cations (2+ charge), typically Calcium and Magnesium, in your water. Carbonate Hardness (KH) is a measure of the alkalinity of you water and it's ability to resist a drop in pH (acidification). The two measure different things which are independent of each other, so a high GH doesn't mean a high alkalinity/KH. Likewise, a high KH doesn't mean your water's "hard", ie, has a high concentration of Ca and Mg. Since GH is a general measurement and doesn't specify actual concentrations of Ca and Mg independently of each other, it's entirely possible to have a high GH that is primarily due to a high concentration of Ca or Mg and low concentrations of the other.

            This is where Equilibrium comes in. It contains GH boosting and RO/DI remineralizing ions; Ca, Mg, S, K, Fe, and Mn in proper ratios for keeping healthy plants. Keep in mind that the materials Equilibrium is made from are all nutrients your plants need in high amounts in order to survive. For this reason, and to make sure your water is chemically balanced for your shrimp, I would strongly suggest using only RO/DI remineralized with Equilibrium and stop mixing with tap. This will allow you to precisely control GH and plant-essential mineral nutrients without concern for an imbalance.

            To answer your question, yes, Alkaline Buffer is what you'll need to use to maintain KH. Since you're adding CO2 it is very important to maintain a stable KH in order to maintain a proper pH.

            2- Processed natural soil substrates: Given the nature of the material, they do take GH and KH ions out of the water so you'll need to monitor them closely for the first few weeks/month. They also put off organic acids for the first couple of months, which will cause a drop in pH on top of what the CO2 does.

            My recommendation would be to do 25% water changes every other day with 100% RO/DI reconstituted with Equilibrium and Alkaline Buffer to your desired GH and KH. If possible, it's best to keep this water in a separate container where you can adjust GH/KH without worrying about fluctuations inside the aquarium. If this isn't possible, make sure to mix the Equilibrium and Alkaline Buffer in separate containers, I find a 500mL measuring cup excellent for this, then add the liquid in small doses until you've reached your targets. Doing so will help prevent overdosing and stressing your shrimp.

            3- Nitrogen (N) and phosphorus (P): N and P are macronutrients; elements required by plants in high quantity to make fundamental chemicals and procure energy from the carbohydrates they produce via photosynthesis. Not adding N and P is a sure-fire way of killing your plants and causing significant algae issues in planted aquaria. Adding Flourish Nitrogen and Flourish Phosphorus as directed will prevent deficiency and death of your plants. I would consider this the baseline dose which may need to be increased to meet the needs of your plants if they begin to show signs of deficiency.

            This chart describes what each plant nutrient is used for and the signs of deficiency. Flourish-Constituents-Deficency.pdf

            I hope this has helped. If you have any further questions please don't hesitate to respond.

            Kind regards,


            • #7
              I actually think I understand now. So I guess I have 2 big questions.
              1. I can afford to do RO/DI only for up to 50% but anything more than that I have to use tap water. The thing is also I used about to 27gallons to fill up my tank. If I didn't use tap then I wouldn't have any KH or GH at all. Now I can use alkaline buffer and equilibrium in separate containers as asked. However how would I dose? For a 50% water change I'd need about 12 to 13 gal of RO/DI. For 30% I'd need 8 gal of RO/DI. Do I does only for those amounts or for the whole tank in each container?
              What would my dosage be To get a stable 6.5 4 or 5 KH with Alkaline buffer? What would be my dose with Equilibrium? I dont want my PH to swing high like I've seen other people's from just bumping up 2.8dkh.
              2. Should I still by Acid buffer today although my CO2 and substrate are doing it already.
              3. In your opinion why does Tropica plant company have us add shrimp on 3rd day from their app to kill off algae before the cycle finishes? Why do they state not to dose fertilizers yet and when you start to use one with no nitrogen or phosphorus?

              *I dont want any algae if I can help it. I'm only running 6 hour light cycle for a few weeks.


              • #8
                I need that carpet to spread asap too! Thank you so much for answering questions. I love Seachem


                • #9
                  Also when should I start dosing for plants?


                  • #10
                    Hello Aquaticluptonian,

                    I understand the need to reduce RO/DI, I've been in the same situation. In your case, I would have a single separate container to hold your water mix so you can adjust parameters to you liking before adding it to the tank. This will allow you to dial in your KH and GH and provide stable water quality for all your water changes. Since you're adding CO2 Acid buffer is unnecessary as the CO2 will acidify the water. In this case getting your KH stabilized is essential, which is where Alkaline Buffer comes in. With pH stability being an important thing to you, I would highly recommend getting a quality pH controller for your CO2 system. This will allow your system to turn on/shut off CO2 input as needed to maintain pH in the range you want. If this is not possible, continue with the timer method I discussed above. Since CO2 acidifies water there is no way around pH swings. Using Alkaline buffer with CO2 will help keep pH swings from being too much or happen too quickly. Starting CO2 an hour before lights-on will cause the pH drop to happen over an amount of time that your fish can easily handle and adjust to. The same goes for shutting it off prior to lights-out. A dose of 2 tsp (12 grams) of Alkaline Buffer should get you between 4 and 5 dKH since you're mixing RO/DI and tap. In this case I would add 1 tsp then measure KH 30 minutes later and add more as needed to reach 5 dKH. For precision weighing, our digital-spoon-scale.php will allow you to accurately measure the mass of Alkaline Buffer and Equilibrium for precise dosing. Measuring by mass is much more accurate than volumetric (tsp, etc) measurement as mass is a constant.

                    As far as Equilibrium is concerned, adding it as directed on the label to reach your desired GH will be enough. Keep in mind that you'll need to monitor GH a couple of times a week to start while the substrate and plants absorb its components from the water. I typically add it a couple of times per week, depending on plant growth, to provide the minerals it contains. If you use it to maintain GH you'll be adding it in sufficient quantity to compensate for plant uptake.

                    To dose Alkaline Buffer and Equilibrium between water changes I recommend getting a 500 mL measuring cup and mixing them with some water then dosing that instead of adding them directly to the tank. It's best to do this separately for each one to avoid saturating the water and potentially reducing dissolution.

                    Regarding the Tropica method; I haven't used it myself so I can't speak directly to it, but I do know it's common in a number of European countries to have NO3 and PO4 levels in water be much higher than we have in the US. Here in the US it's important to give your plants a full spectrum of fertilizers from day 1 to ensure they have all of the nutrients they need to establish and grow. Trimming, transport, and sitting in a retailer's stock tanks often causes the plants to use up nutrient and energy stores prior to the end-user putting them in their systems so they need nutrients from the start to replenish stocks and adjust to the aquarium environment. On top of the regular inorganic fertilizers, Envy can help significantly with this as it adds numerous vitamins and amino acids plants can take up directly and use right away, reducing the plants' need to spend energy and resources making them, allowing them to use those resources toward establishment.

                    Adding shrimp soon after starting a fully planted aquarium is common practice to help reduce the algae that grow while the tank's ecosystem establishes. Since you'll be adding fish relatively quickly, I recommend waiting to add shrimp until you've found a maintenance routine that keeps water quality stable. In this case, doing frequent 20-25% water changes (twice a week or more), using Purigen and adding Stability from the start will go a long way toward keeping good water quality and reducing "early tank algae". Algae are inevitable in all planted aquariums, even Amano's (I've seen a number of them in person). All we can do is practice good husbandry and properly dose our tanks to maintain plant health, which will minimize algae.

                    I hope I've sufficiently answered your questions. If not, please let me know and I'll address the specifics you need clarification on.

                    Kind regards,
                    Last edited by Tech Support PE; 04-14-2020, 16:08.


                    • #11
                      Thank you so much. So my LFS sold me some Amanos and gave me a bag of 10year old gravel to put in my system to kick the cycle faster. My hairgrass is melting back a little too. I think I may have to go in and pluck dead pieces today (what do you think?) So now its stabilizing and PH is hovering at 6.7, KH 3, GH 6. I guess my only question would be now is...
                      1. If I stay with RO/DI only, should I dose for the whole aquarium for 1 to 2 KH or just the replacement water (I now know either way to mix in separate containers, I have 3 5 gallon containers).
                      2. Will my plant fertilizer that does have NPK cause algae? How long should I do 2 water changes a week. I'm waiting to do mine Thirsday for when my other plants come.


                      • #12
                        You're very welcome. How are your Amanos doing? If you've got them in there then I'd keep them as they will help control some types of algae. It's extremely common for new plants to have die-off as the large majority of them, especially the potted ones, are grown hydroponically with their stems and leaves above water. The die-off you're noticing is most likely due to the plant losing its emergent leaves as it adapts to a fully submerged environment. I would definitely make sure to siphon those out when doing water changes. Since most of these dying leaves, as well as the dead and decaying ones, release a lot of organic compounds into the water, using Purigen to remove those that have dissolved into the water column (DOC) as well as doing frequent water changes to remove the physical debris will go a long way toward preventing algae for the entire life of the aquarium. I kept planted aquaria for 20 years before coming to Seachem and always ran Purigen in my tanks for this reason. It's my #1 chemical filtration medium for planted tanks and won't run one without it.

                        I would dose both the replacement/water change water and the tank. Reconstituting the RO/DI to consistent concentrations will be your main source of stable GH and KH supplementation while small doses between water changes will be what maintains the parameters you want.

                        Fertilizing and algae is a complex, but important topic. Over the years I've found that dissolved organic compounds (DOC; the stuff Purigen removes) and an imbalance in light, CO2, and nutrient input are the two main contributors to algae. Therefore, it's essential to keep the water column (Purigen) and substrate (siphoning/water changes) clean. Under circumstances where DOC is controlled and CO2 input is sufficient to meet plants' needs based on the amount of light they get, insufficient and/or imbalanced fertilization can contribute to algae. If your plants don't get enough of what they need then their cell membranes can start to break down causing DOC leakage which promotes periphyton (algae growing on the plants). The same can be said for imbalanced nutrients; especially N and P. This situation is very common when using an "all-in-one" fertilizer where the individual nutrient concentrations can't be controlled. For example, dosing for N often causes insufficient or excessive P since it's included in the product and can't be specifically targeted. This is why the Flourish and Aquavitro lines of plant supplements are single-nutrient solutions; they allow you to target specific concentrations of the major plant-essential nutrients; N, P, K, and Iron. Equilibrium is an exception for Ca, Mg, and S, but since it provides Ca and Mg in appropriate ratios, and S in non-limiting amounts, it does an excellent job as a stand-alone product for those. Although it adds K and Fe as well, those two are used in large quantities by plants and are best added as your plants need. In a heavily planted tank with vigorous growth, plant uptake of all of those often exceeds what a single dose at a water change can provide so keep an eye on GH and add it as needed to maintain it. You'll eventually figure out how much your tank needs and will be able to dose it accordingly. As a planted tank advocate and educator I've always been a proponent of single-nutrient dosing. While it may seem like a lot of bottles and a possible hassle to dose them individually, doing so is fundamental to providing properly balanced nutrient input and long-term plant health.

                        Regarding the twice-weekly water changes; I normally do them for the first month after setting up a new tank. If this is a costly endeavor for you, doing a 25/75 mix of RO/DI and tap will be ok as long as you're able to continue providing consistent GH and KH. Speaking of which, I'd do your next water change prior to adding the new plants to make sure the water's as clean possible to give you a bit of a buffer to accommodate the results of die-off. Looking at the pH and KH you've listed, it looks like you're in the sweet spot for CO2 injection; keep it up!

                        Kind regards,
                        Last edited by Tech Support PE; 04-15-2020, 09:21.