Out of Whack Water Chemistry

[Donmarco]

I have a 125G reef tank, fully stocked with hard and soft coral and six fish. I have a 35G sump and the setup is nearly 3 years old. Recently I started having trouble maintaining water chemistry, after a long and stable period. CA and dKH took a dive so I increased (well below manufacturer's maximum daily dosage recommendations) daily 2-part dosing. I'm using Two Little Fishes C-Balance. For the past week I've dosed daily in equal parts of C-Balance, 60 ml per day. CA levels rose a little and are stable at 250, but well below 400 where they've been for more than 2 years. dKH however has rocketed almost off the charts, today reading at 14 dKH! pH is 8.4. I'm not sure what to do to balance the water chemistry. I'm shooting for higher CA levels, lower dKH, and pH at about 8.3-8.4. I don't have a CA supplement, only the 2-part mix. Any suggestions? Thanks for your help.

 

Mark

[surf&turf]

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

 

See if this helps.

[tpallas]

Magnesium?

[tpallas]

To put it differently....sounds like too much alk dosing and not enough magnesium.

[YBeNormal]

I think this article, "When Do Calcium and Alkalinity Demand Not Exactly Balance?", will help explain the issue and what to do about it. It's one of the best explanations about calcium/alkalinity demand and balancing I have read and one I kept referring back to when my tanks were running. Happy reading and I hope this helps!

[Donmarco]

Magnesium?

 

You're asking if I dose Magnesium? Yes, actually, I'm dosing every other day. I use Brightwell Aquatics Magnesion and dose according to package instructions. I also carefully dose iodine, but only after testing and then only in small amounts if necessary.

[Donmarco]

I think this article, "When Do Calcium and Alkalinity Demand Not Exactly Balance?", will help explain the issue and what to do about it. It's one of the best explanations about calcium/alkalinity demand and balancing I have read and one I kept referring back to when my tanks were running. Happy reading and I hope this helps!

 

That's really a helpful article. Thank you. I was surprised to read that lower dosage may be required, which seems counter intuitive when CA is so low. I'll reduce dosage for the next several days and see what happens.

[Origami]

You've been given some good references for what to do when your calcium and alkalinity don't match. However, there are probably reasons why you've gone from balanced to very unbalanced that you should consider first. The very first thing you need to do before embarking on radical changes is to seek independent confirmation of your test results. This is very important as false reports can cause you to introduce big changes that can be harmful. So, before you add too much, be sure to check and double check your test results, using fresh test kits or with the help of another reefer. Once you get confirmation and are confident that your chemistry is out of whack, make your changes deliberately and carefully, watching the livestock in your tank for signs of distress.

[Steve175]

I would recommend testing your Mg level and dosing it up to 1400. Your test kits may be too old and I would consider replacing them. Salifert makes very good Alk, Ca, and Mg kits or, alternatively, Hanna makes very accurate Alk and Ca checkers (though would still need the Salifert Mg).