Help Is there a cheat sheet for remineralizing RODI water?

[LeperKuN]

I notice some people would say "20ppm of CaSO4" and similar. Is there a cheat sheet somewhere to dose for 3dGH of CA:MG? And what's the range of desirable ratio and why?

I don't understand rotala butterfly stuff.

 

[Art]

I notice some people would say "20ppm of CaSO4" and similar. Is there a cheat sheet somewhere to dose for 3dGH of CA:MG? And what's the range of desirable ratio and why?

I don't understand rotala butterfly stuff.

Well, first, Happy BIRTHDAY!!!

Second, let's take a step back. Can you tell us a bit about your aquarium so we can assist with the water setup?

I know the calculators are a learning curve.

 

[LeperKuN]

Well, first, Happy BIRTHDAY!!!

Second, let's take a step back. Can you tell us a bit about your aquarium so we can assist with the water setup?

I know the calculators are a learning curve.

Thank you, Art. I have Syngonanthus, Eriocaulon, and some other soft water plants. I've been using straight RODI water with 0ppm TDS and then adding about half gallon of tap water. I would add more tap water when I notice CA/MG deficiency. My tank is 20 gallon (UNS 60U). I'd like to get rid of the guess work and use numbers for consistency.

 

[Art]

OK thanks.

So, I would recommend the following:

1. Go download and complete the Fertilizer Regime Template @GreggZ put together. This will help organize you and will help us quickly see what you're doing and suggest tweaks, etc.
2. I agree. I'm not a fan of mixing with tap water as you never know what you're going to get. Therefore, I would get a hold of powdered fertilizer from one of our sponsors so that you're ready.
3. To reconstitute RO water with zero TDS , I go with the traditional GH booster that contains potassium, calcium and magnesium. The break down is 3:3:1. You can buy it pre-mixed now-a-days so I don't worry about doing it myself. Now you can easily use Rotala Butterfly's calculator for your size aquarium. I usually shoot for 5 dGH. Of course, this will depend on plants with some liking a higher calcium or magnesium level so look out for that. We are working on a plant database that will capture and share this data.
4. Now the only thing left is to put the water in the tank and then dose your remaining fertilizer to reach the targets you want to hit. Again, the calculator will help you reach them and tell you exactly how much to add.
5. Finally, please take my word for it, be religious about documenting everything in the template above. It will be invaluable for you in the long run.

Hope that helps, my friend. Please post any follow up questions here and let us know how it goes!

 

[GreggZ]

I notice some people would say "20ppm of CaSO4" and similar. Is there a cheat sheet somewhere to dose for 3dGH of CA:MG? And what's the range of desirable ratio and why?

I don't understand rotala butterfly stuff.

Trust me you can understand the Rotala Butterfly stuff. It's really quite easy once you see how it's done.

The first thing you need to understand is that dGH is made up of primarily Calcium and Magnesium. So we add together the dGH added from Ca (Calcium) and the dGH added from Mg (Magnesium) to get the total dGH.

The most common ratio of Ca:Mg is 3:1. However many folks like myself and others that I know are closer to 2:1. Either way it's not going to make any dramatic difference, we are talking fine tuning here.

The only things you really need are Calcium Sulfate (CaSO4) and Magnesium Sulfate (MgSO4). There are lots of ways to buy them including any online store that sells aquatic plant fertilizers.

So now let's see how Rotalabutterfly works. In this example I am calculating how much CaSO4 to add to a 40 gallons of water to raise Ca to 20 ppm. As you see it tells you how much CaSO4 to add, and also shows what it will raise the dGH to. So in this case adding 13.01 grams (or tsp equivalent) of CaSO4 into a 40 gallons of water will raise the Ca to 20 ppm and bring dGH to 2.8.



If you understand that then you would do the same to calculate for MgSO4. At 20 ppm Ca you could calculate Mg from 7 ppm to 10 ppm in be in a good range. You would then add the dGH from Mg to the dGH from Ca to get your total dGH.

And notice I referenced 40 gallons of water not a 40 gallon tank. That is an important distinction. After a water change we want to dose the new incoming water to our dGH targets. So for instance in my 120G tank I perform a 70 gallon water change. So I calculate my dosing to raise 70 gallons to my target. In case that's Ca 15 ppm, Mg 7.5 ppm for a total dGH of 3.83. But again don't get too caught up in the details. There is no magic ratio or a magic amount for any tank. We just want it in a range where there is enough but not too much. I hope that makes sense.

 

[LeperKuN]

OK thanks.

So, I would recommend the following:

1. Go download and complete the Fertilizer Regime Template @GreggZ put together. This will help organize you and will help us quickly see what you're doing and suggest tweaks, etc.
2. I agree. I'm not a fan of mixing with tap water as you never know what you're going to get. Therefore, I would get a hold of powdered fertilizer from one of our sponsors so that you're ready.
3. To reconstitute RO water with zero TDS, I go with the traditional GH booster that contains potassium, calcium and magnesium. The break down is 3:3:1. You can buy it pre-mixed now-a-days so I don't worry about doing it myself. Now you can easily use Rotala Butterfly's calculator for your size aquarium. I usually shoot for 5 dGH. Of course, this will depend on plants with some liking a higher calcium or magnesium level so look out for that. We are working on a plant database that will capture and share this data.
4. Now the only thing left is to put the water in the tank and then dose your remaining fertilizer to reach the targets you want to hit. Again, the calculator will help you reach them and tell you exactly how much to add.
5. Finally, please take my word for it, be religious about documenting everything in the template above. It will be invaluable for you in the long run.

Hope that helps, my friend. Please post any follow up questions here and let us know how it goes!

Ahh that reminds me. I do have Shrimp King remineralizer that I was saving for when I have a RODI system but forgot about it. Boy it sure was expensive. I do have gypsum for CaSO4. What's a good source for MG? Is it necessary to remineralize the water with potassium or is it better to use it in macro fertilizer?

 

[Freshflora]

Ahh that reminds me. I do have Shrimp King remineralizer that I was saving for when I have a RODI system but forgot about it. Boy it sure was expensive. I do have gypsum for CaSO4. What's a good source for MG? Is it necessary to remineralize the water with potassium or is it better to use it in macro fertilizer?

I would say it’s more common for experienced people to prefer to use Gypsum for CaSO4 and Epsom Salt as a source of MgSO4 and then add potassium separately to the amount you want along with your other macros (nitrate and phosphate) rather than use a commercial remineralizer that also contains potassium because the potassium comes at such a high ratio to the calcium and magnesium in them. Also because of expense as you’ve experienced. Also important to note that Gypsum (CaSO4) is in Rotala Butterfly as CaSO4.2H2O and Epsom Salt (MgSO4) as MgSO4.2H2O. I believe there is a close copy of each or at least one that reads either CaSO4.7H2O or MgSO4.7H2O which aren’t the same thing and which you don’t want to accidentally choose when you’re using the calculator.

 

[LeperKuN]

I would say it’s more common for experienced people to prefer to use Gypsum for CaSO4 and Epsom Salt as a source of MgSO4 and then add potassium separately to the amount you want along with your other macros (nitrate and phosphate) rather than use a commercial remineralizer that also contains potassium because the potassium comes at such a high ratio to the calcium and magnesium in them. Also because of expense as you’ve experienced. Also important to note that Gypsum (CaSO4) is in Rotala Butterfly as CaSO4.2H2O and Epsom Salt (MgSO4) as MgSO4.2H2O. I believe there is a close copy of each or at least one that reads either CaSO4.7H2O or MgSO4.7H2O which aren’t the same thing and which you don’t want to accidentally choose when you’re using the calculator.

Thank you!! I'm going to try and use rotala butterfly again after your explanation.

 

[Joel Armstrong]

I would say it’s more common for experienced people to prefer to use Gypsum for CaSO4 and Epsom Salt as a source of MgSO4 and then add potassium separately to the amount you want along with your other macros (nitrate and phosphate) rather than use a commercial remineralizer that also contains potassium because the potassium comes at such a high ratio to the calcium and magnesium in them. Also because of expense as you’ve experienced. Also important to note that Gypsum (CaSO4) is in Rotala Butterfly as CaSO4.2H2O and Epsom Salt (MgSO4) as MgSO4.2H2O. I believe there is a close copy of each or at least one that reads either CaSO4.7H2O or MgSO4.7H2O which aren’t the same thing and which you don’t want to accidentally choose when you’re using the calculator.

Hi,

I've only just started to use Rotala Butterfly myself. I was a bit confused as to what I should enter into the nutrient calculator when it came to CaSO4, as there are two similar, CaSO4.1/2H20 and CaSO4.2H20. I'd reached out to Gregg Zydeck to ask which to enter, and he had said "It's almost certainly CaSO4.2H20"

For MgSO4, Rotala Butterfly only lists MgSO4.7H20, which I believe is also called Epsom Salts.

Please correct me if I'm incorrect here.

Joel

 

[Freshflora]

Hi,

I've only just started to use Rotala Butterfly myself. I was a bit confused as to what I should enter into the nutrient calculator when it came to CaSO4, as there are two similar, CaSO4.1/2H20 and CaSO4.2H20. I'd reached out to Gregg Zydeck to ask which to enter, and he had said "It's almost certainly CaSO4.2H20"

For MgSO4, Rotala Butterfly only lists MgSO4.7H20, which I believe is also called Epsom Salts.

Please correct me if I'm incorrect here.

Joel

Yeah that’s completely correct. My mistake you want CaSO4.2H20 and MgSO4.7H20. Thank you for correcting me on that!

 

[Joel Armstrong]

Yeah that’s completely correct. My mistake you want CaSO4.2H20 and MgSO4.7H20. Thank you for correcting me on that!

Haha

No problem, and I meant no disrespect to you at all. I just wanted to clarify for myself and other new comers using Rotala Butterfly etc.

Thank you

 

[KrangDog]

Is there a cheat sheet somewhere

To answer this question, yep, I wrote one in Excel. Rotala Butterfly is good, but I was worried that it would be down at some point when I needed it and got sick of calculating all of my dosages individually. So I did the logical thing and spent way more time than sensible writing some calculators.

The one you're probably most interested in for your purposes is the GH Booster Calculator. It takes a water volume, a desired GH in degrees and a resired Ca:Mg ratio and spits out the required addition of CaSO4.2H2O and MgSO4.7H2O. It can be found in the Secondary Calcs sheet.

There's also a few other calculators.

One for calculating dosages for remineralising using KNO3, KH2PO4, K2SO4, CaSO4.2H2O (gypsum), MgSO4.7H20 (epsom salt) and NaHCO3 (baking soda). That one also works if you're using a reservoir and can't pump out all of the water. It'll calculate a reduced addition to account for the residual.

There's also two for mixing up liquid ferts if you don't want to front load. I use this for doing my micros. One works for DIY unchelated ferts and one for chelated trace mixes.

There's some basic instructions, but they were written mostly as reminders for me and may not be particularly clear to others.

It's good to understand this stuff, so I'd suggest following Gregg's advice and spend some time with Rotala Butterfly. My tank is still garbage, but it's less garbage than it was before I understood all of this. Anyway, have a play if you want.

 

[Art]

Thank you for posting that. And, frankly, the time it took to put it together. Awesome!

I'm going to have a look. Do you have a background in chemistry?

 

[KrangDog]

Do you have a background in chemistry?

No true chemistry background, but did a few mandatory courses at uni. In truth, something I was awful at back in my school days. But once you understand molar masses, it's all fairly intuitive. Understanding this isn't essential. I know plenty of local people who run much nicer tanks than mine and have next to no understanding of this, but it certainly adds to my enjoyment of the hobby and I suspect it would for some others too. Like anything, you can take it as far as you'd like to. It gets beyond what @LeperKuN was asking, but someone may find it interesting.

Take MgSO4.7H2O for instance. The molar mass of Mg from Google is 24.305, SO4 is 96.06, and H2O is 18.01528. Add these up, taking into account the 7 x H2O molecules and you end up with a total molar mass of 246.48. This essentially means that in a 246.48g sample of MgSO4.7H2O, 24.305g of that will be Mg.

You can then calculate percentages. So the percentage of Mg in MgSO4.7H2O is (24.305/246.48)x100 = 9.86%.

So if you add 1 gram (1000mg) MgSO4.7H2O to 1L of water, 9.86% or 98.6mg of that is Mg. So you end up with 98.6mg of Mg/litre of water, 98.6mg/L, or 98.6ppm.

This is all that Rotala Butterfly and my calculator really do. You could also calculate the amount of SO4 and H2O that you're adding if you found it relevant.

 

[Art]

Got ya. I had to learn this back in the day when we created the Fertilator calculator for APC. Edward, from PPS Pro fame, was doing the calculations and I was coding them on the backend. Let me tell you, it sounds easy but when you have to include the calculations for commercial products, combinations, etc., it gets complex!

I agree with you though. I think it's a good exercise for anyone interested to learn more about.