# Alkalinity



## TerryMik (Feb 23, 2006)

2006-02-22
I understand that as alkalinity increases, calcium will precipitate out thereby reducing dissolved calcium levels. Can anyone tell me why alkalinity rises and how to correct it?

Thanks !!!!!


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## jiggy (Jun 27, 2004)

whats ur ph?.. easiest way to lower dkh is to do waterchanges


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## Raptor (Jan 3, 2003)

Give us a little history here. What are you dosing, Do you add kalk, 2 part, or a ca/rx, add any additives and what? Do you add magnesium or know your magnesium levels?
Whats your ph, alk, and calcium? How much are you loosing everyday?
What corals do you have primarily? Size tank?
You could percipitate calcium by driving up the alk to high, and it could be because you adding a substance that is driving it up high.


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## TerryMik (Feb 23, 2006)

Raptor said:


> Give us a little history here. What are you dosing, Do you add kalk, 2 part, or a ca/rx, add any additives and what? Do you add magnesium or know your magnesium levels?
> Whats your ph, alk, and calcium? How much are you loosing everyday?
> What corals do you have primarily? Size tank?
> You could percipitate calcium by driving up the alk to high, and it could be because you adding a substance that is driving it up high.


*2006-02-28*

Thanks for your reply. While I am a "Junior Member" I've actually been in the aquarium hobby for close to 40 years, but my salt water experience is somewhat limited. I live in an area where our tap water is very soft (10 to 15 ppm Calcium Carbonate) so I am accustomed to having the hardness and pH drop due to the metabolic activities in the tank............ but in the salt water environment, I am finding the pH and alkalinity rise  as more specimens are added to the tank and hence the drop in the calcium levels. While I have run into this situation in other tanks, the one that I am currently dealing with has a net water volume (including sump) of about 300 Gallons. There are 4 to 5 inches of live sand on the bottom as well as ample live rock. Filtration is provided by a trickle filter and protein skimmer. The tank was first established with the live rock & sand. Other life forms were introduced on a gradual but steady basis once the tank had completed the initial nitrogen cycle (the live rock was a mixture of cured, uncured and established) and included a large carpet anemone, a few crabs, an 8" Tridacnid clam, a 6" Brain Coral, and a few anemones and soft corals. At this point the system was maintaining a pH of 8.1 with an alkalinity of 2.5 meq and calcium at 420 ppm. Once fish were introduced things began to change (currently there are a dozen 1" Green Chromis, 3 Blennies (3"), two Percula Clowns (2"), one Skunk Clown (2") and a 7" Unicorn Tang). Calcium concentration is down to 360 ppm, alkalinity at 3.5 meq and ph @ 8.4 or 8.5 but I have not tested magnesium. The only substances added have been the two part "Kent" calcium supplements. Even when added on a daily basis (at the manufacturer's recommended maximum), there was no measurable increase in calcium levels.

My basic question, then is *why is the alkalinity increasing???* What is the easiest way to control this? Would adding buffers to bring the ph down solve this problem? Some of the pieces of live rock seem to be getting brittle, so it would appear the calcium is dissolving - the system is trying to "achieve" an equilibrium of + 450 ppm of calcium, as would be expected.

Any suggestions that would result in this situation being reversed would be of great help and most appreciated.

tm


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## 00nothing (Mar 26, 2004)

I am far from an expert when it comes to this stuff but if i remeber right from reading any increase in calcium should also lower your alk so my suggestion would be to stop using the 2 part and swith to a calcium only additive something such as kalkwasser


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## TerryMik (Feb 23, 2006)

00nothing said:


> I am far from an expert when it comes to this stuff but if i remeber right from reading any increase in calcium should also lower your alk so my suggestion would be to stop using the 2 part and swith to a calcium only additive something such as kalkwasser


*2006-02-28*

Thanks for your input. From all that I have read, it actually works the other way. It is the rising alkalinity that causes the Calcium to precipitate out. So my question remains (assuming that the rising alkalinity is the sole root of this evil) (LOL) _Why is the alkalinity rising ?_

.............. and if there are other potential causes of this problem, what are they???

I'm no expert either, but I guess we are all on here just trying to learn more. Thanks to everyone who offers suggestions !!

tm


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## Raptor (Jan 3, 2003)

I am thinking you are adding more of the 2 part that the tank is using. You COULD have drove the ph, and alk high enough to percipitate out the CA. IMO
Your ca load is pretty good if you have coraline algea on your rocks, on that size of a tank. Guessing that you do have alot of rock.
Coraline algea uses alot of ca, and other trace elements, but will use up ca. I would dose some calcium clhoride. (AKA Kent turbo calcium)
and dose the 2 part accordingly to your tank needs.
Say you have alk good ph good, and ca low. Dont add both just add some of the ca part. Or turbo calcium to achive the ca leves that are ideal.
I doubt the rock is dissolving. Have you noticed any ca buildup on pumps, powerheads magnets, and on the rock and glass?
If its percipitating you would see it on those above.


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## Trillion (May 10, 2004)

when I go out and invest n my marine life water testing kit will it tell me what my water calciumm, nitrates etc. need to be meaning will it have the exact #s that I need to be at.
Other than that I reallyy don't hve to have any thing else right, I just gotta watch for ick and eminities on my corals correct? If I do start to get eminities how do I get rid of them
Thanks ahead folks


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