Let's talk about Alkalinity, Calcium and Magnesium in an SPS Tank

[biecacka]

Got my mag up to about 1200. Calcium is about 500, and alk is holding around 8.3.
Good start?

Corey

 

[Scorpius]

Got my mag up to about 1200. Calcium is about 500, and alk is holding around 8.3.
Good start?

Corey

Better. When I first had my tank setup 500 Calcium was not uncommon. I like to keep my magnesium around 1400.

Here's a nifty chart for Ca/Alk ratio so you have an idea of how in balance things are.

DKH Ca
4.50 393
4.75 395
5.00 397
5.25 398
5.50 400
5.75 402
6.00 404
6.25 405
6.50 407
6.75 409
7.00 411
7.25 413
7.50 414
8.00 418
8.25 420
8.50 422
8.75 423
9.00 425
9.25 427
9.50 429
9.75 431
10.00 432
10.20 434
10.50 436
10.75 438
11.00 439

 

[Zhuisken]

Alkalinity: 10
Calcium: 500
Magnesium: 1500

Dana Riddle had a interesting talk at MACNA last year on high alkalinity levels and increased photosynthesis in corals. He has a lot of good research on corals growth and coloration.

Good water chemistry, lighting, and flow can make for some great looking corals!

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[JB NY]

Alkalinity: 10
Calcium: 500
Magnesium: 1500

Dana Riddle had a interesting talk at MACNA last year on high alkalinity levels and increased photosynthesis in corals. He has a lot of good research on corals growth and coloration.

Good water chemistry, lighting, and flow can make for some great looking corals!

Sent from my SM-G935V using Tapatalk

Dana uses pocillopora a lot in his studies. Those things grow like weeds in the worst of circumstances so I am not surprised that they might do good with high alk. I've never found low or high alk to have much impact on growth. Better to keep ca around 450 and Mg 1350-1450.

 

[Zhuisken]

Dana uses pocillopora a lot in his studies. Those things grow like weeds in the worst of circumstances so I am not surprised that they might do good with high alk. I've never found low or high alk to have much impact on growth. Better to keep ca around 450 and Mg 1350-1450.

Consistency I believe is the key when your parameters is within a reasonable range. Alk, Ca, Mg.

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[five.five-six]

Arggg, I need to read this entire thread again!

 

[10Seconds]

My Alk has been 12 or higher for the last 6 months. Hasnt had any noticiable benefit so I am going to drop it back down. Have tried as high as 14.

On the other hand, it didnt cause any trouble except on one SPS that i bought from the LFS which they kept at 7.5 Alk and it went through a rough adjustment. Its doing fine now too.

Im going to let it gradually fall back to 9 over the next couple months.

 

[gatreef]

I find that dosing Kalkwasser and watching the corals for growth, polyp extension and coloration is the easiest method for me. I test for calcium, alk and ph but not very often.

 

[five.five-six]

I test weekly

 

[JCOLE]

I gotta say, I am loving my Trident!


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[SantaMonica]

Maybe the automated systems can have a "scrubber aware" option, which allows for more alk when a scrubber is growing. Yes another switch.

 

[five.five-six]

I forgot if this calculator is in this thread, it’s older than this thread and handy as heck!

http://reef.diesyst.com/chemcalc/chemcalc.html

 

[Reef Bass]

For me, both high (>10) and low alk (<7) can be problematic. Low alk especially.

I also have noticed times when it seemed dosing "balanced" amounts of alk and ca wasn't yielding reasonable numbers. I used to have this 24" back to front of tank Idaho Grape Monti cap. that was a ginormous calcium sponge.

And adjusting dosing to accommodate ever changing populations and growth of stony corals can provide additional challenge.