Alkalinity - Where do you want it? Low? High? Middle?

[that Reef Guy]

So I was told that you want your Alkalinity to be between 7 and 11.

Then I was told you want it on the higher end (11).

I was just wondering.

Do some types of Corals like Low Alkalinity and some like High Alkalinity?

Or do you always regardless of the reason want High Alkalinity of around 11?

So I am looking at adding Buffer to one of my Aquariums.

My Alkalinity in my three aquariums is:

12
10
7

Unless you think otherwise should I raise the Alkalinity in the Aquarium where it is Low at 7 by Adding Buffer so I can raise it to 11?

Will that make my Corals Grow?

 

[Lazys Coral House]

I shoot for 9.5. You are going to get a lot of variation in this thread. Those that bacteria dose find keeping it lower the corals do better those that don't typically go higher.

 

[Reefing Madness]

You should keep it between 8-12. But there are others that will tell you they can keep it at 6-7. But I try to keep mine under 10 and above 8.
Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com

 

[Duffam3434]

My tanks sitting right around 9 as well.

 

[Palting]

Higher alk numbers do help stony coral growth, all the way up to 11dKH. However, some people find problems with abiotic calcification and precipitation if numbers are kept that high.

I actually asked Dr. Holmes-Farley this question. With our current dosing capabilities, we can now pretty much dial in a specific number for alk in our tanks and keep it there. So, what would be an ideal specific alk number within that range 0f 7-11 for an SPS dominated mixed reef? His answer? 8dKh. So, that's where I keep mine, with calcium at 440 and mag at 1350.

 

[ritter6788]

I keep mine around 7-8. Sometimes it gets up to 9 but I try to keep it 7-8 dkh. Only reason I do is because the alk of the ocean is 7. I can't find any reason not to stay as close to ocean parameters as possible.

 

[TighTT]

I keep my SPS dominant tank at 8.