How to balance Ca/Alk in the reef aquarium?

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FWIW, the slow calcium rise is expected with limewater (kalkwasser). I used a low calcium mix (normal IO) for that reason.

If you want the same pH effect as the kalkwasser, you'll need to use sodium hydroxide.

If you just want the same alk effect, then you can use bicarbonate, carbonate, or hydroxide for the alk dosing.

The 7 dKH of alk is right.

You can dose that over any period you want.

If you spread it out over 14 days (0.5 dKH per day), then you'd dose about half as much limewater during that time.

@Randy Holmes-Farley

If I use NaOH, I calculate that I need 374mg mixed in 5ml of RODI to get 7 dKH based on your recipe.

Obviously this is too concentrated for me to drip over 7 to 14 days.

Did I miscalculate?

Any suggestions on dilution that will still provide pH boost equal to Kalkwasser?
 
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@Randy Holmes-Farley

If I use NaOH, I calculate that I need 374mg mixed in 5ml of RODI to get 7 dKH based on your recipe.

Obviously this is too concentrated for me to drip over 7 to 14 days.

Did I miscalculate?

Any suggestions on dilution that will still provide pH boost equal to Kalkwasser?

Any dilution will provide the same boost, if you add the appropriate amount of water. For example, that 374 mg can be dissolved in 5 L instead of 5 mL.
 
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Any dilution will provide the same boost, if you add the appropriate amount of water. For example, that 374 mg can be dissolved in 5 L instead of 5 mL.

@Randy Holmes-Farley

I wasn't clear on my questions:
1. Is 374mg of NaOH mixed in 5ml of RODI the right amount to get 7 dKH based on your recipe (yes I can dilute)?
2. I want to dose it throughout the day like Kalkwasser to achieve a similar pH boost. If I dilute it, how far should I dilute and still get a similar incremental pH bump?
 

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Sodium hydroxide is exactly 1.32 times as potent on a weight basis than is sodium carbonate.

So any recipe or calculator value for sodium carbonate, you use 1.32 times less.

Translating to dKH involves knowing the tank volume.

In this calculator


A 100 gallon aquarium boosted by 7 dKH takes 50.1 grams of sodium carbonate, so it takes 37.8 grams of sodium hydroxide.
 
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Sodium hydroxide is exactly 1.32 times as potent on a weight basis than is sodium carbonate.

So any recipe or calculator value for sodium carbonate, you use 1.32 times less.

Translating to dKH involves knowing the tank volume.

In this calculator


A 100 gallon aquarium boosted by 7 dKH takes 50.1 grams of sodium carbonate, so it takes 37.8 grams of sodium hydroxide.

Thanks @Randy Holmes-Farley
 
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So I ended up using TM Classic Balling Alk to do my adjustments. I lowered my kalk dosing by 0.3dKH, left my AFR dosing alone (0.3dKH), and have been dosing 0.3ish TM Balling Alk.

So this will take about 24days.

I'm 11 days in and have had little to no impact on my pH. I'm guessing the the CO2 scrubber is working a little harder.
 

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