Playing with calcium numbers

[AllTheCorals]

I feel that I’ve finally mastered parameter manipulation. I understand what results playing with alk in relation to nutrients, lighting and flow can do for my tank.

Calcium im still lost on. Many run 400 and just as many run 475+. I can’t find info on the results I could expect running more or less calcium would achieve.

My tank is sps dominated.

Alk:8.5
Cal:440
Mag:1500
N03:10-15
P04: .01-.02
40-70x flow
300 par on sandbed 8b Ati and xho

Thank you!

 

[Dr. Reef Verified Sponsor]

Cal has a wide range of acceptance.
400-500
Personally I prefer to keep it within 400-460

 

[Dan I]

As previously stated, Cal can be kept in the range of 400-500 ppm. Many aquarist keep it around 425-450 ppm. I personally like to keep mine around 425 ppm.

 

[AllTheCorals]

I understand the range it should be in. Having the cal at 400 will have one effect on coral while 500 will have another effect.

Same like alk can be 7-11. At 7 you get more color and 11 more growth. TIA!

 

[BigJohnny]

I understand the range it should be in. Having the cal at 400 will have one effect on coral while 500 will have another effect.

Same like alk can be 7-11. At 7 you get more color and 11 more growth. TIA!

I disagree with this actually. Cal is something that just needs to be in sufficient quantity. The difference between 400-500 has no significant impact on coral health/growth/coloration by itself, imo and ime. That's the reason you can't figure it out.

I also don't think that you get more color automatically at 7 dkh. Sure growth is theoretically faster at higher dkh but not sure where your getting better color from.

 

[AllTheCorals]

That’s what I was looking for! So it’s just a number to keep consistent. Thank you very much, I couldn’t find any info on this except relating to coralline.

Would a lower number slow down my coraline growth?

With alk from my research and limited experience with sps ive seen that running a cleaner tank will result in better coloration with most corals. Along with a cleaner tank a lower alk to avoid burnt tips.

I originally had my alk at 9.5-10 when starting this system with no3 around 25-30. My nutrients began to drop overtime as the tank matured while keeping a consistent alk. I started noticing white tips and learned I needed to either raise nutrients or lower alk.

Of course there are always exceptions to everything, but I’m speaking in generalities. I use to grow a ton of LPS with zero testing and random water changes before I really got into this lol

 

[BigJohnny]

That’s what I was looking for! So it’s just a number to keep consistent. Thank you very much, I couldn’t find any info on this except relating to coralline.

Would a lower number slow down my coraline growth?

You've mastered parameter manipulation in an sps dominated tank and your asking me if calcium effects coralline growth lol? Are you sure your not a newbie just looking for info? You don't have to hide ; )

 

[madweazl]

I run at the lower range (400-415) and coralline still grows at a pain in the butt rate (e.g. grows to fast on the tank, pumps, and overflow). Magnesium is also lower that most at right around 1300.

 

[AllTheCorals]

You've mastered parameter manipulation in an sps dominated tank and your asking me if calcium effects coralline growth lol? Are you sure your not a newbie just looking for info? You don't have to hide ; )

Isn’t this the place to ask? I’m not here swinging a big dick with all the answers.

I’ve had all my parameters within 1% for over a year. Cal reactor and everything running well, no hiccups. Nearly 200 sps varieties in my system that are all growing faster than I can believe lol

Now I’m trying to maximize my setup and make my life easier. I scrap a ton of coraline every week and I’m trying to confirm if lowering the cal will slow that down without effecting the coral growth.

If what you’re saying is correct, the coral growth won’t be effected. What about the coraline?

 

[AllTheCorals]

I run at the lower range (400-415) and coralline still grows at a pain in the butt rate (e.g. grows to fast on the tank, pumps, and overflow). Magnesium is also lower that most at right around 1300.

Have you ever ran cal higher? Did it grow faster at a higher number?

 

[madweazl]

Have you ever ran cal higher? Did it grow faster at a higher number?

I've run it higher, it didnt make a difference.

 

[AllTheCorals]

I've run it higher, it didnt make a difference.

Thank you!

 

[madweazl]

Thank you!

Dont consider my results gospel

 

[AllTheCorals]

Dont consider my results gospel

I had a feeling that was the case or it would have been talked about much more like other parameters. Makes my life easier. I use reef crystals as is except for lowering the alk. Thanks again!

 

[Randy Holmes-Farley Verified Community Expert]

I understand the range it should be in. Having the cal at 400 will have one effect on coral while 500 will have another effect.

Same like alk can be 7-11. At 7 you get more color and 11 more growth. TIA!

What people are saying is that isn't true.

Calcium becomes not the limiting factor for coral growth somewhere in the 300's, and above that the particular value has no substantial effect on most organisms. They get what they want and are happy with it. They just ignore it after that.

The only issue with very high calcium (within the range of what is actually attainable) is increased chances of abiotic precipitation, but the effect is small. Doubling calcium from 400 to 800 ppm is only equivalent int hat context to a 0.3 pH units rise in pH, or a rise of alk from 7 to 14 dKH.

 

[AllTheCorals]

What people are saying is that isn't true.

Calcium becomes not the limiting factor for coral growth somewhere in the 300's, and above that the particular value has no substantial effect on most organisms. They get what they want and are happy with it. They just ignore it after that.

The only issue with very high calcium (within the range of what is actually attainable) is increased chances of abiotic precipitation, but the effect is small. Doubling calcium from 400 to 800 ppm is only equivalent int hat context to a 0.3 pH units rise in pH, or a rise of alk from 7 to 14 dKH.

Thank you for clarifying!

 

[BigJohnny]

Isn’t this the place to ask? I’m not here swinging a big dick with all the answers.

I’ve had all my parameters within 1% for over a year. Cal reactor and everything running well, no hiccups. Nearly 200 sps varieties in my system that are all growing faster than I can believe lol

Now I’m trying to maximize my setup and make my life easier. I scrap a ton of coraline every week and I’m trying to confirm if lowering the cal will slow that down without effecting the coral growth.

If what you’re saying is correct, the coral growth won’t be effected. What about the coraline?

Sorry, I misconstrued your intentions. I thought you were making sure that lowering your calcium WOULDN'T slow down your coralline growth because you didnt want that to happen, which is typically something newbs focus on, growing coralline. More advanced reefers with SPS dominate tanks dont care about coralline or want less of it, which i now see is what you are trying to obtain. Just FYI, saying you've mastered parameter manipulation is definitely a form of swinging it lol.

As far as your question, I doubt that lowering your cal from say 450-400ppm for example would have any noticeable impact on coralline algae growth, assuming all else equal. IME Alk/Ca/Mag actually have a very minimal impact on whether coralline grows in your tank/at what rate, as long as they are within typical ranges. I have had 3 tanks with nearly identical parameters at one point, and they all grew it differently. One didnt grow it at all. There is a lot more to it than that and I doubt you will be able to significantly impact its growth in either direction.

If you are tired of scraping, some urchins eat coralline and might help, but research thoroughly because they have downsides as well, some more than others.

Good luck