Lowering Carbonate Hardness

[marybeth1975]

I have had my tank for about 4 months. I have just checked my carbonate hardness and it is 15. The first time I checked it, it was normal. My PH is 8. It has been 8 every since I have started my tank. For the life of me I can't get it above 8. I have bought the buffer to raise PH but it still does no good. I know these two are related. I know that 15 is too high for carbonate hardness. How can I lower it? Is there anything out there I can buy? I am pretty regular on my water changes. Any advise would be great.

[old salty]

Check the kH on freshly mixed salt water (a day after you make it.) Some salts are high in this (not necessarily a bad thing.) Are you topping off with limewater? The kH will naturally decline as corals and coralline algae consume it, but limewater will maintain the level.

As for pH, 8 isn't too bad. Don't try to move several parameters at once as it usually leads to more problems. Let the kH decline on its own over the next week or so, then you can tackle the pH (again, it's not a cause for immediate concern.) Also, the pH will fluctuate over the course of a day and color changing kits aren't as accurate as a pH meter would be.

[marybeth1975]

Thanks for the info. I was pretty nervous. I didn't know how "quickly" I should react. No Im not topping off with limewater. I guess I should be? I didn't think my pH was too bad. But I have heard two different stories on that. One will say its too low and others will say its ok. So I should top off with limewater and let the kH decline?

[WaterKeeper]

Hi Marybeth,

It sounds to me that your aquarium is located in an area with somewhat high CO₂ concentrations. It isn't all that low nor is the alkalinity all that high. If it bothers you I'd work on the pH first. Here is a great article by Randy on Low pH, Causes and Cures (http://www.reefkeeping.com/issues/2004-09/rhf/index.php). It should help you raise it and I think that in itself may also lower the alkalinity shortly thereafter.

[NeuroLarry]

http://reef.diesyst.com/

This is a nifty calculator. Also you may want to go to the reef chemistry forum.

[marybeth1975]

Thanks guys so much. I will definitely read the info given.

[jdieck]

<a href=showthread.php?s=&postid=7416390#post7416390 target=_blank>Originally posted</a> by NeuroLarry
http://reef.diesyst.com/

This is a nifty calculator. Also you may want to go to the reef chemistry forum.

If the flash version of the calculator do not work with your browser try the traditional calculator flash free.
http://jdieck1.home.comcast.net/chem_calc3.html

Your alkalinity does not need supplementation at this time but check your Calcium, it might.
Note that Limewater adds Alkalinity too not only Calcium, you need to wait for it to drop so no Kalk shall be added.
With your alkalinity level if you need to increase Calcium only I would recommend using a Calcium Chloride based supplement like Kent TurboCalcium or ESV Calcium Chloride which will increase Calcium without alkalinity.