Why do a lot of reefers keep a lower alk in their tank (8-9)?

[glb]

Thanks everyone. I’ll only be growing LPS in this tank. I appreciate all the feedback!!!!

 

[glb]

Many keep around 7. Especially sps low nutrient tanks.

Why do you think lower is better?

 

[Earl Karl]

Why do you think lower is better?

As I explained earlier, nutrients must be in balance with alkalinity to keep up with the pace of skeleton and tissue growth.

Lower alk. is only better for low nutrient tanks. Nutrients correlate to tissue growth while alkalinity correlates to skeleton growth. In low nutrient tanks, high alkalinity will cause the skeleton to grow faster than the tissue, resulting in burnt tips in mainly acros. With low alk., you won't get the growth, but you will have amazing colors. This is more catered to fully matured reef packed with colonies.

In higher nutrient tanks, lower alkalinity would create disgusting color (subjective to point of view however) with poor growth. With higher alkalinity along with higher nutrients, both can keep up with each other's pace resulting in much faster tissue and skeleton growth, however, due to higher nutrients, you won't get those amazing colors. More catered to frags that you just want to grow out fast as possible.

I have mine at the happy medium however, I still get fast growth and amazing colors.

 

[Doctorgori]

Personally for me it takes less brain power and hub bub in the low 8s

 

[EMeyer]

When the alkalinity of the ocean is 7ish,I respectfully suggest the question should be rephrased: why does anyone run anything but 7ish?

I get the theoretical arguments about increasing calcification. But in my experience, high alk kills corals, while I have my best survival and growth at NSW levels. Usually SPS. But even zoas can suffer. Not in my tanks, in my tanks zoas appear to be immortal. But I hear about this "zoa melting" thing. And I've noticed that when I sell people zoas, the only time they dont survive is when people put them in tanks with unnaturally high alk (>8)

The only beneficial deviation I've seen from NSW levels is magnesium, which montis seem to love at unnaturally high levels (>1300). Every other time my water chemistry has deviated from NSW my corals have suffered.

My 2c

 

[Earl Karl]

When the alkalinity of the ocean is 7ish,I respectfully suggest the question should be rephrased: why does anyone run anything but 7ish?

I get the theoretical arguments about increasing calcification. But in my experience, high alk kills corals, while I have my best survival and growth at NSW levels. Usually SPS. But even zoas can suffer. Not in my tanks, in my tanks zoas appear to be immortal. But I hear about this "zoa melting" thing. And I've noticed that when I sell people zoas, the only time they dont survive is when people put them in tanks with unnaturally high alk (>8)

The only beneficial deviation I've seen from NSW levels is magnesium, which montis seem to love at unnaturally high levels (>1300). Every other time my water chemistry has deviated from NSW my corals have suffered.

My 2c

Read my latest post in this thread.

As I explained earlier, nutrients must be in balance with alkalinity to keep up with the pace of skeleton and tissue growth.

Lower alk. is only better for low nutrient tanks. Nutrients correlate to tissue growth while alkalinity correlates to skeleton growth. In low nutrient tanks, high alkalinity will cause the skeleton to grow faster than the tissue, resulting in burnt tips in mainly acros. With low alk., you won't get the growth, but you will have amazing colors. This is more catered to fully matured reef packed with colonies.

In higher nutrient tanks, lower alkalinity would create disgusting color (subjective to point of view however) with poor growth. With higher alkalinity along with higher nutrients, both can keep up with each other's pace resulting in much faster tissue and skeleton growth, however, due to higher nutrients, you won't get those amazing colors. More catered to frags that you just want to grow out fast as possible.

I have mine at the happy medium however, I still get fast growth and amazing colors.

 

[happyhourhero]

Mine is closer to 7. Can’t vote.

 

[piranhaman00]

Alk of 8.5-9.0 with high nutrients, PO4 0.1-0.15ppm and NO3 5-10ppm. LPS love it! (I think)

 

[ReefGeezer]

8.0 for my SPS tank. It seems to work well. For some reason, that's where it is easiest to keep stable. Alk demand in my system is moderate. Dosing lime water maintains it as long as do my water changes on time. I use Fritz salt. If I remember correctly, it mixes up around 8.5.

 

[HawaiianReef]

I use IO and keep my tank at 7.5.

Lower ALK in IO is simple, but requires a bit of easy math and muriatic acid.

easy peasy math.....
Water volume x Decrease in ALK x 0.123 = Muriatic acid to add in ML

Example:
30G water volume with a 2.5 DKH drop(typical for me and IO)

30 x 2.5 x 0.123 = 9.2ML

Muratic acid?!
Ok, I guess this is a normal procedure. Forgive my ignorance, I'm still learning.
What grade muratic acid do you use?

 

[Earl Karl]

Muratic acid?!
Ok, I guess this is a normal procedure. Forgive my ignorance, I'm still learning.
What grade muratic acid do you use?

You could also use Seachem Acid Buffer, does the same thing to lower alk. but dose SLOWLY. Very dangerous to reef when overdosed as byproduct is CO2, lots of it.

 

[blasterman]

Fellow reefer I know has a massive SPS tank dominated with dinner plate size montipora caps of all color. Another SPS buddy of mine keeps massive table acros growing in a 400+ gallon tank.

Both keep their dKH around 7.5 and go out of their way not to go higher. Montipora guy reports dKH above 8.0 starts to hurt the caps.

I've found that higher alk levels combined with elevated nutrient levels helps softies grow at obscene rates, but for SPS I've never found elevated alk levels help anything, and in ULN situations can be a time bomb. Just because amatuer salt mixes (reef crystals being the most notorious) have dKH in the range of 12-13 doesn't mean that's where it should be.

Pet Peeve / rant here, but we need to stop endorsing newbies adopt 2 part dosing from the start. Joe Smith who starts a 90gallon tank and throws half a dozen 1" SPS frags in it doesn't need a two part. Alk consumption in young tanks is never 'balanced' as alk will get consumed at a much higher rate than calcium, and in bigger tanks the sheer volume of calcium is enough that minimal water changes should replace it faster than a stupid bottle of diluted sidewalk de-icer.

 

[Soldja12]

Use ultamitereef.net calculator. Gives you the appropriate dkh to balance calcium. They work hand in hand

 

[Bramzor]

Many keep around 7. Especially sps low nutrient tanks.

Same here, I keep it at 7.5

 

[glb]

As I explained earlier, nutrients must be in balance with alkalinity to keep up with the pace of skeleton and tissue growth.

Lower alk. is only better for low nutrient tanks. Nutrients correlate to tissue growth while alkalinity correlates to skeleton growth. In low nutrient tanks, high alkalinity will cause the skeleton to grow faster than the tissue, resulting in burnt tips in mainly acros. With low alk., you won't get the growth, but you will have amazing colors. This is more catered to fully matured reef packed with colonies.

In higher nutrient tanks, lower alkalinity would create disgusting color (subjective to point of view however) with poor growth. With higher alkalinity along with higher nutrients, both can keep up with each other's pace resulting in much faster tissue and skeleton growth, however, due to higher nutrients, you won't get those amazing colors. More catered to frags that you just want to grow out fast as possible.

I have mine at the happy medium however, I still get fast growth and amazing colors.

My tank isn’t low nutrient because I don’t plan to have SPS, just LPS and softies. NO3 between 5-10 and PO4 between 0.02-0.06. For my tank, it sounds like a higher alk might make sense.

 

[d2mini]

7.5-8.5 for me.
I'm fine with it swinging around in that range, no issues.
And this leaves me a little wiggle room for it to fall lower or rise a little higher.
My tanks are always low on nutrients.

 

[JimWelsh]

Trident says my alk is nominally 9.5; Hanna says it’s 10.5 ..... whom to believe ....

The Trident.

 

[homer1475]

Muratic acid?!
Ok, I guess this is a normal procedure. Forgive my ignorance, I'm still learning.
What grade muratic acid do you use?

31.45%. I buy it right at my local Ace hardware store.

Transchem Muriatic Acid Ace Hardware

It doesn't take much, I'm still on the bottle I bought 2 years ago, and it's only like 20$ for the gallon.

 

[SeaDweller]

I keep mine between 7.3-7.6 dkh because my nutrient levels are low; plus I don't see the need to go over 8 dkh.

 

[Earl Karl]

My tank isn’t low nutrient because I don’t plan to have SPS, just LPS and softies. NO3 between 5-10 and PO4 between 0.02-0.06. For my tank, it sounds like a higher alk might make sense.

At that level, around 8.5 dkh is good. Most importantly, stick to a number you choose.