Is There A Optimal Alkalinity Level?

[William Morris]

Looking for thoughts on if there is an optimal alkalinity level for a mixed reef.
BRS states that they believe 9.0 to be an optimal level.
For euphyllia, some of my suppliers like 7.5 to 8.
In your experience what level seems to work the best in your setup?
I have been targeting 9.0 based on BRS's input.
Thanks

 

[lapin]

8.5 for me. I mix red sea blue and red sea coral pro when doing water changes and I run a calcium reactor

 

[piranhaman00]

7.0 to 7.5

 

[Hydrored]

I run 7.25, more because things grow and that’s what the salt I use roughly mixes to (TM Pro Reef)

 

[Brandon3152134]

I run at 10 most of my sps are growing pretty well I think

 

[Brandon3152134]

I have seen brs do experiments running higher alk and had more growth and I've always ran my tank at 10 so I've just kept it there

 

[WallyB]

Optimal Alk is "STABLE".

Preferred Range is flexible. Most corals will Adapt if you keep things "stable"

I personally like 8.0, since it gives me a bit of room to drop and not go below 7.0 if I fall behind on watching/testing.

I also like to pick my Tank Alk based on the Salt I use. (ie during water changes, I like my Tank ALK to be the same as Salt Alk, so the Water Change does not shift my Water Parameter). I do Water Changes Autmatically/Daily.
I also Dose Two Part so that's my Alk Stabilizer for Alk Consumption. It also keeps my Calcium and Mag in line.

In my case, I use Red Sea Blue Bucket which has a 8.0 alk at 35ppt Salinity. So things Match up.

If you want to use your Water Changes, to help keep ALK stable for Consumption.... then then things change.

 

[Crustaceon]

It’s pretty subjective. Most of it has to do with providing the correct amount of nutrients in order to keep up with alk/cal/mg consumption. So let’s say you run 9dkh. Your corals might not take off because your nitrates and phosphates are out of whack at that alkalinity where they’d be more in line at 8 or 7dkh.

 

[mike550]

8.5

 

[William Morris]

Would you target the Alk level based on the corals you keep?
SPS at a certain level
LPS
Softies / Mushrooms

 

[William Morris]

It’s pretty subjective. Most of it has to do with providing the correct amount of nutrients in order to keep up with alk/cal/mg consumption. So let’s say you run 9dkh. Your corals might not take off because your nitrates and phosphates are out of whack at that alkalinity where they’d be more in line at 8 or 7dkh.

Interesting - I had not thought of or run across anything that referenced the interplay between Alk and nitrates/phosphates.

 

[Rmckoy]

Mine seams to be stable at 7.5-7.7

 

[Randy Holmes-Farley Verified Community Expert]

Looking for thoughts on if there is an optimal alkalinity level for a mixed reef.
BRS states that they believe 9.0 to be an optimal level.
For euphyllia, some of my suppliers like 7.5 to 8.
In your experience what level seems to work the best in your setup?
I have been targeting 9.0 based on BRS's input.
Thanks

There is no optimal alk level for all reefs and all aquarists. There are valid reasons to maintian any alk from 7 to 11 dKH, IMO.

Higher alk (say, 9-11 dKH) promotes faster coral growth, especially SPS. If growth is the main goal, higher alk is desirable. But if nutrients are not high enough to support the higher growth, high alk can risk burnt tips.

Lower alk can allow more color, especially if nutrients are lower, but low nutrients can risk dinos.

 

[lelandmarine]

Agree with RHF, Stability, chose a number and try to keep it there

 

[William Morris]

There is no optimal alk level for all reefs and all aquarists. There are valid reasons to maintian any alk from 7 to 11 dKH, IMO.

Higher alk (say, 9-11 dKH) promotes faster coral growth, especially SPS. If growth is the main goal, higher alk is desirable. But if nutrients are not high enough to support the higher growth, high alk can risk burnt tips.

Lower alk can allow more color, especially if nutrients are lower, but low nutrients can risk dinos.

Randy - do you have a paper or a thread that explains the correlation between alk and nitrates / phosphates?
Appreciate your explanation above.

 

[Randy Holmes-Farley Verified Community Expert]

Randy - do you have a paper or a thread that explains the correlation between alk and nitrates / phosphates?
Appreciate your explanation above.

Not really. There isn't much more to it than what is written above.

In general, I suggest that aquarists maintain alkalinity between about 7-11 dKH (2.5 and 4 meq/L; 125-200 ppm CaCO3 equivalents).

Many aquarists growing SPS corals and using low nutrient systems have found that some SPS corals suffer from "burnt tips" if the alkalinity is too high or changes too much. It is not clear why this is the case, but such aquaria are better served by alkalinity in the 7-8 dKH range. The only viable explanation that I have seen is that the coral skeleton can grow faster than the tissue growth can keep up, leading to thin tissue that is easily damaged at the growing tips.

 

[William Morris]

Thanks Randy

 

[Cjeippert]

Not really. There isn't much more to it than what is written above.

In general, I suggest that aquarists maintain alkalinity between about 7-11 dKH (2.5 and 4 meq/L; 125-200 ppm CaCO3 equivalents).

Many aquarists growing SPS corals and using low nutrient systems have found that some SPS corals suffer from "burnt tips" if the alkalinity is too high or changes too much. It is not clear why this is the case, but such aquaria are better served by alkalinity in the 7-8 dKH range. The only viable explanation that I have seen is that the coral skeleton can grow faster than the tissue growth can keep up, leading to thin tissue that is easily damaged at the growing tips.

I just watched the brs video a couple months ago and upped alk to 9.0 from 8.0. Nitrate was undetectable, but everything but a hammer and acan were doing great. Most corals started looking bad so I turned my skimmer off for 4 days until I got nitrates to a steady 5. So now I only run skimmer at night to prevent nitrates from dropping too low. With my low nitrates and burnt sps, I am thinking about slowly going back to 8.3 dkh. Hard to keep everything happy in a mixed reef.

 

[monkeyCmonkeyDo]

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[monkeyCmonkeyDo]