HELP - Calcium and Hardeness won't stay high

[YellowTang]

Hi,

I have a reef for about 7 months and the thing that gives me more headaches is mantaining calcium and hardeness in high values.

I use an osmolator for top-off water with Kalkwasser that adds more or less 2 litres of water into the aquarium.
With this method I only get 380 mg/l of calcium and about 125 mg/l or 7 dkh of carbonate hardness.
Too low won't you agree ???

I then started adding addictives like dkh pro buffer or part A+ part B both from kent marine till I reached 11 dkh or 200 mg/l hardness.Then used kalkwasser to mantain and a couple days later both values started falling again.

Why ??? am I suposed to substitute kalkwasser with addictives ??

Please help me find a solution

Thanks

 

[jackdp]

What is in the tank that is using up your calcium and carbonate? Do you do regular water changes with freshly mixed SW...how often? 380 mg/l Ca and 7 dkh are just on the low side. Post some more detail about your system to get some better help. In the meantime, check out this article about solving calcium and alkalinity problems.

http://www.advancedaquarist.com/issues/nov2002/chem.htm

And here's one that can help choose a supplementation scheme...

http://www.advancedaquarist.com/issues/feb2003/chem.htm

There's a lot of science in there but very good info if you can digest. If you have any questions ask away! HTH

 

[YellowTang]

Well, my aquarium is about 55 gallons with 50 kg live rock.

I do weekly water changes of about 7 galons.

I read somewhere something about magnesium interacting with calcium and hardness. What is te relation ?

thanks

 

[GrndHog]

I know if you start using Oceanic salt your calcium will go up. Some claim that they have just stop using all additives because of this salt. Me included.

 

[steve-s]

I read somewhere something about magnesium interacting with calcium and hardness. What is te relation ?

Mg helps keep alk an Ca in solution together. They are chemically at odds and one is always trying to push the other out of solution. The Mg is what prevents that.

As long as the Mg is in the 1200-1400 ppm range (3x the Ca) depending on where Ca is normally maintained, it should not be an issue. Given the fact that your alk reading is not bad, it appears your simpley having a small problem maintaining the Ca. If Mg where deficient, your problem would be the other way 'round. Alk would be low and Ca higher.

As jackdp indicated above, your levels are on the lower side of the scale but not really something to be overly concerned about. The only thing you need do is elevate the Ca a tad (400-410 ppm) to get a bit more in balance over the alk.

 

[YellowTang]

Hi there,

well I analysed my top off water to make sure that every parameter was ok and guess what ??

Ca = 40 mg/l
dKH = 2,2 º or 40 mg/l
pH=8,5

Is this correct or my top off water keeps pushing my aquarium water parameters down ??

 

[steve-s]

Top off water will have little if any effect on your overall water specs. Given most use (or should be) RO water which is basically void, it's not an issue. What you should be looking at is the specs of newly mixed SW after aerateing with a powerhead and heater for 12-24 hrs. That will tell you wether of not simple weekly water changes are needed based on the CaCO3 demand in your tank. If not, then deciding on a supplimental scheme would be the next step.

Cheers
Steve

 

[YellowTang]

ok, the parameters from my sw weekly change are :

Ca = 380 mg/l
dKH = 7,8
pH = 7,9

Should I correct this parameters before using it ??

 

[steve-s]

Was that from the tank or newly prepared SW?

The Ca is a bit low based on the alk but not a huge issue. You might want to add a bit of CaCl to bring it up a bit. It would be a better balance in the 405-415 (ish) ppm range. Just be sure the salt has been mixed for at least 12 hrs before hand.

If you tested the pH in the AM it's okay but if later in the day, it's low. At about midday or later, pH should be 8.0-8.3 depending.

Cheers
Steve

 

[YellowTang]

These parameters are from newly prepared SW.

Strange, I thought that Alk was low and calcium was low but not to worry about.

 

[steve-s]

The alkalinity is fine. The only issue with the Ca is if it gets used up at all, it will create an even larger imbalance making it harder to fix as time goes by. If you "tweek" the Ca a bit with each water change, it will help eliminate the possible problem.

If you have any type of coralline growth I am quite sure both alk and Ca will get used up at least some. With corals, I would actually suggest some sort of suppliment dosed directly to the tank. These levels as they are will be hard to maintain and keep balanced if so.

Keep testing every few days and see what the rate of depletion turns out to be. That will help to detrmine what if anything extra might need to be done.

Cheers
Steve

 

[YellowTang]

When you say "tweak" a little in each water change, do you mean using some addictives in change water ??

 

[gibbiceps]

I use an osmolator for top-off water with Kalkwasser that adds more or less 2 litres of water into the aquarium.

Is it fw ro water? If it is buffer it with liquid reactor by kent that will help alot!!

 

[steve-s]

When you say "tweak" a little in each water change, do you mean using some addictives in change water ??

Yes, simpley adding small amounts of CaCl to the SW before it goes in the tank can help. You can also add the CaCl to the tank directly but be sure in either case you follow the directions carefully and be sure to test before/after each addition.

Cheers
Steve

 

[YellowTang]

Hi,

Can I tweak alk too ??

 

[steve-s]

You could but your saltmix doesn't need it.

Cheers
Steve

 

[YellowTang]

Excelent,

After one week my result where :

Ca = 300 mg/l
dKH = 10º
pH=8,3

Tweak Ca in change water and dKH in aquarium, plus kalkwasser !!!

Thanks guys

I think I got there. I 'll wait to see !!