Raising Calcium but not alkalinity

[ovicez2004]

I tested my tank this morning:
Alk 9.9
Calc 390
No3 12
Po4 0.07
Ph 8.0

Can anybody tell me how to rase Calc without raising Alk? Or, shoud I raise calcium? 390 seems a little low... Tank is 9 mo old. Mixed reef. Thank you.

 

[Joe31415]

This...this is what you use to raise calcium without changing alkalinity.

Pharma Calcium Chloride 1-Gallon Mix (Single Use)

Ultra-pure Calcium Chloride for 2-part dosing in your reef tank! Bulk Reef Supply 2-part additives are the perfect solution to replenish the intake of calcium and alkalinity coral consumes when it grows. Using only pharmaceutical based ingredients allows you to keep a cleaner reef with fewer...

www.bulkreefsupply.com

Do you have corals in the tank yet? If you don't I'm not sure the calcium (or alk) numbers really matter all that much.

 

[mike550]

There are plenty of calcium additives. I‘m sure folks will have a
lot of recommendations but BRS Calcium Chloride is a nice start

 

[exnisstech]

You said mixed reef so assuming you have coral just dosing a calcium supplement should be fine. Everything I've read says alk and calcium go hand in hand and should be dosed in equal amounts. That method doesn't work for me. My issue is opposite of yours. I use esv 2 part and my calcium creeps up to 500 and I back off for a while on dosing it.

EDIT: I like to keep it around 440 but corals don't seem to mind when it gets higher.

 

[Johnic]

Will adding too much calcium lock up the pumps and risk turning the sand to rock?

 

[Randy Holmes-Farley Verified Community Expert]

Will adding too much calcium lock up the pumps and risk turning the sand to rock?

Yes, but adding an appropriate amount will have no such effect. Calcium up to at least 550 ppm is perfectly fine.

 

[Johnic]

Yes, but adding an appropriate amount will have no such effect. Calcium up to at least 550 ppm is perfectly fine.

Adding it slowly I assume, over a week ? Or can it be applied all at once ?

 

[Randy Holmes-Farley Verified Community Expert]

Adding it slowly I assume, over a week ? Or can it be applied all at once ?

When doing a one time correction, I'd limit the rise to 25 ppm calcium per day out of caution for impurities in it, not because the calcium rise itself is going to cause issues.

 

[Johnic]

When doing a one time correction, I'd limit the rise to 25 ppm calcium per day out of caution for impurities in it, not because the calcium rise itself is going to cause issues.

Is there a risk for precipitation ?

 

[Miami Reef]

When doing a one time correction, I'd limit the rise to 25 ppm calcium per day out of caution for impurities in it, not because the calcium rise itself is going to cause issues.

Are these impurities organic (can be removed with skimmer/carbon) or inorganic?

If the impurities was like nitrate, where it doesn’t bind/get removed, then is a ramp really necessary if at the end, the total amount of impurities will be in the water?

Perhaps organisms can adjust to the impurities with a “ramp,” but I want to know what types of impurities you are thinking of.

 

[Randy Holmes-Farley Verified Community Expert]

Is there a risk for precipitation ?

Not by adding it fast, only by adding it excessively. It's not a significant driver of precipitation.

Adding 100 ppm of calcium (400 to 500 ppm) is identical in precipitation potential to a pH rise of 0.1 pH units or an alk rise from 7 dKH to 8.25.

 

[Randy Holmes-Farley Verified Community Expert]

Are these impurities organic (can be removed with skimmer/carbon) or inorganic?

If the impurities was like nitrate, where it doesn’t bind/get removed, then is a ramp really necessary if at the end, the total amount of impurities will be in the water?

Perhaps organisms can adjust to the impurities with a “ramp,” but I want to know what types of impurities you are thinking of.

My concern is heavy metals. They often are not present at sufficient levels to be a concern, but folks use all sorts of brands of calcium chloride that do not contain much purity info. Since raising calcium is never an emergency, there's never a reason to go fast, IMO.

I analyzed a number of brands here long ago (they have likely changed sources/ suppliers since then):

Aquarium Chemistry: Purity Of Calcium Chloride

Randy takes a look at a number of sources of calcium chloride and reports on them.

reefs.com

from it:

Cadmium, on the other hand, is known to be toxic at fairly low levels. Canadian Water Quality Guidelines for the Protection of Aquatic Life suggest a maximum of 0.12 ppb in seawater. [Toxicology][40] tests on marine organisms show toxic effects beginning in the 10-100 ppb range. Consequently, the delivery of 4 ppb (for the two Kent products) over the course of a year may be a concern. The other calcium chloride samples had significantly less cadmium.

Chromium is another potential concern with some of these samples. Canadian Water Quality Guidelines for the Protection of Aquatic Life suggest a maximum of 56 ppb in seawater for chromium III compounds, and 1.5 ppb for chromium VI compounds. Chromium compounds in an aquarium are likely to be chromium III as the chromium VI compounds are highly oxidizing and will rapidly react with organics and other inorganic ions to give chromium III compounds again. Consequently, the delivery of 4-6 ppb of chromium (for the two Kent products) over the course of a year is not likely a significant concern.

 

[Miami Reef]

Yes, I agree. There’s never a reason to rush.

I was mainly wondering if there will be a build up of these impurities with long term use of calcium chloride.

 

[AquaLogic]

You said mixed reef so assuming you have coral just dosing a calcium supplement should be fine. Everything I've read says alk and calcium go hand in hand and should be dosed in equal amounts. That method doesn't work for me. My issue is opposite of yours. I use esv 2 part and my calcium creeps up to 500 and I back off for a while on dosing it.

EDIT: I like to keep it around 440 but corals don't seem to mind when it gets higher.

That method has just raised alk to unhealthy levels for me. I don’t know why that method is pushed so hard.

 

[Miami Reef]

That method has just raised alk to unhealthy levels for me. I don’t know why that method is pushed so hard.

If a 2 part is designed for 1:1 dosing, you should dose equal parts of both to maintain alkalinity.

 

[AquaLogic]

If a 2 part is designed for 1:1 dosing, you should dose equal parts of both to maintain alkalinity.

Alkalinity is more sensitive to test and is more important than pinning down calcium. There shouldn’t be a rush of rising alk “unhealthily” by using alkalinity to gauge how much you souls dose.

Using ESV two part my alkalinity rose to like 13dkh to get calcium to 500 ppm over the course of a week. I can't have 13Dkh. Perhaps there is something going on that I don't understand, but using ESV as directed has not worked well for me. My alkalinity skyrockets when trying to get calc up.

 

[Miami Reef]

Using ESV two part my alkalinity rose to like 13dkh to get calcium to 500 ppm over the course of a week. I can't have 13Dkh. Perhaps there is something going on that I don't understand, but using ESV as directed has not worked well for me. My alkalinity skyrockets when trying to get calc up.

For every 2.8dkh added, calcium will rise about 19ppm.

Calcium’s range is 400-500ppm. Natural seawater is about 420ppm. There’s no reason to boost calcium to 500ppm purposefully.

I said earlier that you should base the two-part dosage on alkalinity. If alkalinity was rising too high, you would have stopped adding the two parts. This is why I mentioned earlier that you should base the two-part dosage on alkalinity: it’s more important and moves more quickly.

If you need to make specific adjustments to calcium, use calcium chloride.

 

[Randy Holmes-Farley Verified Community Expert]

That method has just raised alk to unhealthy levels for me. I don’t know why that method is pushed so hard.

What method? If using a two part raised alk, you used too much. It should always be dosed to maintain alk.

Bear in mind that not all two parts are designed for 1:1 dosing, though they should be, IMO.

 

[Randy Holmes-Farley Verified Community Expert]

Using ESV two part my alkalinity rose to like 13dkh to get calcium to 500 ppm over the course of a week. I can't have 13Dkh. Perhaps there is something going on that I don't understand, but using ESV as directed has not worked well for me. My alkalinity skyrockets when trying to get calc up.

Why would you target 500 ppm calcium? If that was a goal (never should be, IMO), you cannot attain it by dosing both parts of a two part without alk getting too high.

 

[AquaLogic]

Why would you target 500 ppm calcium? If that was a goal (never should be, IMO), you cannot attain it by dosing both parts of a two part without alk getting too high.

I'm running sps heavy and was seeing a great deal of calcium depletion. Perhaps 500 is too high and I should have targeted 450. I wasn't seeing alk drop, it was just rising and rising, so adding ESV 1:1 as directed wasn't working. I'm open to the idea I may have done something wrong, but I don't know what.