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I just want to record these calculations in their own thread to refer back to in other threads.
When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g., Seachem Acid Buffer is this chemical, I think) or sulfuric acid (but that one is harder to get for hobbyists).
Note that these methods reduce pH a lot (and to the same extent), until you aerate adequately, so go very slow in a display and aerate a lot to drive off the excess CO2 that is generated.
Dropping alk by 1.4 dKH when starting at 6.3 dKH will drop pH below 7 (I got 6.9, experimentally). The effect is roughly linear with alkalinity, so starting at 12.6 dKH, a drop of 2.8 dKH will drop the pH to around 7 or a bit lower (depends on the starting pH, of course).
Sodium bisulfate is NaHSO4.
In seawater, it releases H+:
NaHSO4 ---> Na+ + H+ + SO4--
The H+ is what reduces the alkalinity, and the Na+ and SO4-- are not any concern:
H+ + CO3-- --> HCO3-
So, how much is needed?
NaHSO4 weighs 120.1 grams per mole. Thus, 120.1 grams has the potential to reduce alkalinity by 1 mole, or 1 equivalent, or 1000 meq (milliequivalents).
If you were to add that much to 1000 L, you would drop the alkalinity by 1000 meq/1000L = 1 meq/L = 2.8 dKH.
So 1.2 grams per 10 Liters, drops alkalinity by 2.8 dKH.
If you do not have a scale, we can roughly estimate how much is in a teaspoon:
1 cubic centimeter (1 mL dry) weighs roughly 1.44 grams.
A level teaspoon (4.93 mL) will then weigh roughly 7.1 grams.
1 level dry teaspoon of sodium bisulfate added per 100 L of tank water will drop the alkalinity by about 1.7 dKH.
Dissolve it in fresh water before adding it slowly to a high flow area.
DO NOT USE BISULFITE. Note the "i" in the ending vs an "a"
These materials should be fine to use:
https://www.amazon.com/Sodium-Bisul...d=1519584550&sr=8-7&keywords=sodium+bisulfate
https://www.amazon.com/Sodium-Bisul...d=1519584550&sr=8-7&keywords=sodium+bisulfate
When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g., Seachem Acid Buffer is this chemical, I think) or sulfuric acid (but that one is harder to get for hobbyists).
Note that these methods reduce pH a lot (and to the same extent), until you aerate adequately, so go very slow in a display and aerate a lot to drive off the excess CO2 that is generated.
Dropping alk by 1.4 dKH when starting at 6.3 dKH will drop pH below 7 (I got 6.9, experimentally). The effect is roughly linear with alkalinity, so starting at 12.6 dKH, a drop of 2.8 dKH will drop the pH to around 7 or a bit lower (depends on the starting pH, of course).
Sodium bisulfate is NaHSO4.
In seawater, it releases H+:
NaHSO4 ---> Na+ + H+ + SO4--
The H+ is what reduces the alkalinity, and the Na+ and SO4-- are not any concern:
H+ + CO3-- --> HCO3-
So, how much is needed?
NaHSO4 weighs 120.1 grams per mole. Thus, 120.1 grams has the potential to reduce alkalinity by 1 mole, or 1 equivalent, or 1000 meq (milliequivalents).
If you were to add that much to 1000 L, you would drop the alkalinity by 1000 meq/1000L = 1 meq/L = 2.8 dKH.
So 1.2 grams per 10 Liters, drops alkalinity by 2.8 dKH.
If you do not have a scale, we can roughly estimate how much is in a teaspoon:
1 cubic centimeter (1 mL dry) weighs roughly 1.44 grams.
A level teaspoon (4.93 mL) will then weigh roughly 7.1 grams.
1 level dry teaspoon of sodium bisulfate added per 100 L of tank water will drop the alkalinity by about 1.7 dKH.
Dissolve it in fresh water before adding it slowly to a high flow area.
DO NOT USE BISULFITE. Note the "i" in the ending vs an "a"
These materials should be fine to use:
https://www.amazon.com/Sodium-Bisul...d=1519584550&sr=8-7&keywords=sodium+bisulfate
https://www.amazon.com/Sodium-Bisul...d=1519584550&sr=8-7&keywords=sodium+bisulfate