my reef chemistry

[Maudsley]

Need some advice please. I have had a saltwater tank for about 7 months. 170 gal with wet/dry sump...UV sterilizer, protein skimmer. I'm turning over my water 15X an hour with powerheads and mag 12 with 6 foot of head pressure. I have never tested for Alk or calcium or Mg. After reading the reef chemistry articles i decided I'd better get my act together. Here are my readings

Alk=6.1 dkh
Mg=1290
Ca= off the charts
Ph=below 7.4
Nitrates=20
Nitrites=0
Ammonia=0

I just dosed with Kent Marine Pro-buffer DKH, follwed recommeded dose for a 24 hour period 8 capfulls equals treating 160 gals in a 24 hour period. all tests performed with salifert test kits. What should I expect and will ph come up when I get ALK up and Ca go down to acceptable levels?

[bertoni]

I am not convinced that pH measurement is accurate. A second opinion would be useful. How is pH being measured? Some baking soda dissolved in RO-DI water will fix the alkalinity safely. This calculator will help with a dose:

http://home.comcast.net/~jdieck1/chem_calc3.html

For most calcium tests, you can just use two syringes of the titrant and add the results together to get the true calcium level.

Are you using Oceanic salt? That salt commonly leads to this situation. Otherwise, what is being dosed for calcium?

A balanced additive like limewater or a 2-part is a good way to avoid getting the levels out of balance by dosing. This article might help:

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

This article describes a DIY 2-part:

http://reefkeeping.com/issues/2006-02/rhf/index.php

You should be able to wait and let Ca drop on its own. This article discusses such situations:

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

[Maudsley]

Retested PH with another kit...it's 8.0. After taking the tests for ALK and Mg I dosed with the kent marine DHK buffer...this should raise ALK correct, for future dosing if required I'll use the baking soda method as it's alot cheaper....lol.

[Maudsley]

Sorry and the salt being used is Instant Ocean

[Maudsley]

I have used Kalk mix for my topoff....about 2-3 gals per day. By what the articles said I should not have ALk problems....if i read that right. I just installed an RO/DI unit with an auto topoff a week ago....I'm wondering if this is causing the effects I'm seeing

[bertoni]

The Super Buffer is fine as an alkalinity supplement. If all the calcium and alkalinity dosing is done with limewater, the calcium and alkalinity parameters should move in parallel, mostly:

http://reefkeeping.com/issues/2004-12/rhf/index.htm

Every once in a while, adding a little extra alkalinity is needed.

The autotopoff should be fine with RO-DI water.

[Maudsley]

Thanks for all the information....Now that I have the means to test for ALK, Ca, I will keep on top of it more.....not sure why my ALK is down but with all this information it should be easier to maintain...again thanks for the info!

[Maudsley]

2nd day of tests
Alk=8.0
Ca=800
Mg=1280

What is the correct level of Alk 7-11 dkh? Should i shoot for a dkh of 10 or lower?

[Frick-n-Frags]

that Ca is not right. try a different test to verify.

[Maudsley]

I've checked the calcium with two different test kits....salifert....it's over 560, thats as high as the chart goes on this test kit. I used the whole 1ml and it did not change the color. I also used Marine Aquariums by Red Sea....color changed at 800 ppm. I believe the Ca is correct unless both test kits are bad. Some more info on my mistakes....lol. LFS had me put a balance block in, they also had me dosing Ca, mag and iodine once a week. I would have to say my bio-load on Ca was no where as high as what i was putting in the tank, of course my bad for not testing and trusting the people at the LFS. My new test kits by salifert will be arriving in a day or two....I will retest when they come in, I believe i can wait out the high Ca until it comes into acceptable parameters but yesterday after I added DKH buffer and brought that up my Ca did drop alot. Right now I'm getting my Alk up to 9dkh, hopefully that will drop my Ca more into an aceptable range.

[Billybeau1]

I doubt your calcium is that high using Instant Ocean unless it is coming from your water.

On the Salifert kit, when you dispense the whole syringe, if the color does not change, fill the syringe again to the 1 ml line and slowly dispense until the color turns blue. Then add the two values together, i.e. 500 + what ever the second number is.

Mix up a gallon of fresh salt water at 1.026 and test the calcium in it.
This will tell you what you are adding to the tank.

and

[welcome]

[Maudsley]

Thanks for the info on using a second ml and adding to get ca on the salifert test. I will do that.....up until 1 week ago my tank water was mixed with tap water. I just installed a 5 stage Ocean wave RO/DI unit. I have tested the RO/Di water is is clean as a whistle...could have been what came out of my tap. I'll check that

[Billybeau1]

:thumbsup:

[Maudsley]

On third day of testing here are my parameters
Alk 10.9
Ca 900
ph 8.3
Mg 1290

So I've brought my Alk up only had to dose twice.....with the high Ca, can I wait it out till it get used or should I preform a water change? Once i got the alk up my corals began to respond and look much better. I have stopped all dosing of Kalk, and Ca.

[Billybeau1]

The key here is your corals are looking much better. Leave everything alone and let the calcium fall on its own. Check alk every few days and keep it where it is at if you can. :)