Best alkalinity number?

[Sophie"s mom]

Good evening everyone! So as a newbie to keeping coral, I have a question. I finally have stability I. My tank. All corals are good . While I know stability is key, and excepted range is 7 to 12, currently my tank stays at 8. So the question is what number, within the range seems to keep them the happiest? Should I strive for something a bit higher? Like 8.5 or 9? Thank you in advance for any and all input here.

 

[BristleWormHater]

My tank sits a 9dkh my corals love it, I'm sure other people have a better answer lol.
@Randy Holmes-Farley?

 

[Pntbll687]

I keep mine between 8-9dkh. If I test alk and it's in that range, I change nothing and move on.

Calcium and alkalinity uptake are NOT linear. Some days coral will uptake more, some days less. Keep it within a range of about 1dkh and you'll be fine

 

[MERKEY]

Follow what salt mix you use.

It will make water changes and dosing a lot easier as you won't have as hard of a time keeping the same level.

 

[PharmrJohn]

You're gonna find numbers all over the map. Fifteen years ago, I kept mine between 15 and 18 (more on the 15 side). Must have got that from an old timer, as I've actually seen text to keep in this range from the 80s. When I get going again, I'll keep it between 10 and 11 (I'll be using NYOS salt mix)

 

[trini2debone]

You're gonna find numbers all over the map. Fifteen years ago, I kept mine between 15 and 18 (more on the 15 side). Must have got that from an old timer, as I've actually seen text to keep in this range from the 80s. When I get going again, I'll keep it between 10 and 11 (I'll be using NYOS salt mix)

I am curious, how did your corals respond to those numbers?

 

[dwest]

8 sounds good. It will vary through the day so measure near the same time and keep it relatively constant.

 

[PharmrJohn]

@trini2debone --- They were fine. They grew. But I cannot remember how fast they grew. So it may not have been an ideal number to aim for. Too long ago!!!!

 

[dschuffert]

I keep mine around 8, and I use Fauna Marin salt. Years ago, I stayed around 12 and used Red Sea Pro salt. My corals did well with both. As others have stated, stability is key.

 

[eliaslikesfish]

i’m a 9 guy personally.

 

[Justfebreezeit]

I remember people thinking low nutrient tanks should target low alk and vice versa.

Don't know if that's still a thing or was debunked

 

[Salty_Northerner]

My system seems to look and thrive the best at 8.5 dkh. I use Tropic Marin pro reef salt @35.0ppt and All For Reef on a Versa doser and it's pegged at 8.5 .. Makes sense sence the online store I buy coral from keep their entire farm at 8.3. and the transition seems to be stress free on the corals. The local ship sit @11 and I can see they prefer the 8.5 vs the 11 the store keeps it at.

 

[Solo McReefer]

8.315

 

[VintageReefer]

15 years ago I kept my mixed reef around 11dkh

More recently…I kept my current reef around 8 - 8.5. It would drift into the upper 7’s periodically.

For the last week or so I’ve been running an alkalinity controller. I set it for 9.25. This is a max. It will test the water and calculate how much sodium bicarbonate is needed to get the tank to 9.25.

It tests every 4 hours. It’s interesting that some 4 hour spans have 0 consumption and other times I’m dropping .2 dkh.

By leaving it set at 9.25, my tank basically is always 9 - 9.25

 

[Sophie"s mom]

15 years ago I kept my mixed reef around 11dkh

More recently…I kept my current reef around 8 - 8.5. It would drift into the upper 7’s periodically.

For the last week or so I’ve been running an alkalinity controller. I set it for 9.25. This is a max. It will test the water and calculate how much sodium bicarbonate is needed to get the tank to 9.25.

It tests every 4 hours. It’s interesting that some 4 hour spans have 0 consumption and other times I’m dropping .2 dkh.

By leaving it set at 9.25, my tank basically is always 9 - 9.25

I have never heard or an alkalinity controller before! That sounds interesting.

 

[VintageReefer]

KHG

 

[gbroadbridge]

Good evening everyone! So as a newbie to keeping coral, I have a question. I finally have stability I. My tank. All corals are good . While I know stability is key, and excepted range is 7 to 12, currently my tank stays at 8. So the question is what number, within the range seems to keep them the happiest? Should I strive for something a bit higher? Like 8.5 or 9? Thank you in advance for any and all input here.

The best number is one that matches your chosen salt.
Staying at that level makes things easy for you in terms of stability.

 

[Randy Holmes-Farley Verified Community Expert]

Higher alk will give faster hard coral growth in many cases. If you have higher alk, be sure nutrients are not too low or you risk burnt tips, possibly from the skeleton growing faster than the tissue can keep up.

 

[twentyleagues]

What does your salt mix at? I would try and keep it there. Like @Randy Holmes-Farley said Keeping high alk with low nutrients can lead to "burnt tips" so if you trend higher than 10dkh make sure you have a decent amount of nitrate and phosphate available. I saw this years ago when the ulns became a thing I kept my tank at around 11dkh and a lot of my sps started having this issue once n was 5-8 and p was below .08 seemed my tank at 11 dkh liked more in the line of n 15-20 and p of .1-.2. I am not saying do this just what I observed on my end.

 

[Sophie"s mom]

Higher alk will give faster hard coral growth in many cases. If you have higher alk, be sure nutrients are not too low or you risk burnt tips, possibly from the skeleton growing faster than the tissue can keep up.

THank you for your input on this Randy! Do you think aiming for a steady 9 would be acceptable! My NO3 is usually between 25 and 25 ppm. and my PO4 is usually between .03, and currently (as of last night) .11 ppm.