I have Alkalinity problem

[TAC]

I need to raise alkalinity to 8.3/8.2 at least. I did %20 water change and its still 7.2. I was trying to mix half gallon saltwater with 5 grams of reef buffer with wave maker. But its not getting mixed. 3 corals already died. Any suggestions

 

[tbrown]

7.2 should be fine for corals.

To raise it easily you can always use Baking Soda or Soda Ash. Kalk works as well.

https://reef.diesyst.com/chemcalcnew.html
Use your actual water volume, not system volume. I usually do total volume (tank and sump sizes) multiplied by 75% (100 gallon tank is ~75 gallons of water after rock and sand and equipment is added). My 125+30 sump (~20 gallons of water and equipment) was right at 100 gallons for dosing purposes.

 

[Rocks reef]

Agreed. the 7.2 alkalinity is not what is killing your corals. The average global surface ocean pH is 8.1, so you aren't that far off. What could harm corals is raising or lowering alk rapidly.
What are your other parameters?
Kalkwasser will be the easiest for you to use to raise your alk. You could also dose something like AFR, which will help with calcium and mag as well.

 

[tbrown]

Agreed. the 7.2 alkalinity is not what is killing your corals. The average global surface ocean pH is 8.1, so you aren't that far off. What could harm corals is raising or lowering alk rapidly.
What are your other parameters?
Kalkwasser will be the easiest for you to use to raise your alk. You could also dose something like AFR, which will help with calcium and mag as well.

Correction: Baking Soda will be the easiest to raise your alkalinity but kalkwasser may be the easiest to maintain it once raised.

 

[slythy]

What was the Alk of the new salt? What corals are dying? Other parameters? I ran my SPS for a long time at around 7.25 before bumping to 10 to match where I get my corals.

 

[joanropi17]

I need to raise alkalinity to 8.3/8.2 at least. I did %20 water change and its still 7.2. I was trying to mix half gallon saltwater with 5 grams of reef buffer with wave maker. But its not getting mixed. 3 corals already died. Any suggestions

I personally use a magnetic stirrer that j bouth on amazon, it doesn't mean that you have to get one, but make sure that you are using RODI water, do not use saltwater from the tank. Also, make sure that you use the correct portion vs. volume of RODI water. I use the same product with no issues dissolving the material.

However, I don't think the coral is dying becasue the alkalinity level, that's my humble opinion.

 

[Randy Holmes-Farley Verified Community Expert]

However, I don't think the coral is dying becasue the alkalinity level, that's my humble opinion.

It’s not. Alk of 7.2 dKH is higher than anywhere in the ocean.