Normal Ca Very High Alk, a problem?

[josenestor]

Due to a silly newbie mistake I should not be doing I dosed buffer to raise pH when my alk was normal (9 dKH). My calcium was already too high (600 mg/L).

I noticed some of the montipora bleaching and some of the other corals not looking too well.

I checked all parameters, and realized what I had done.

NO3 close to 0
PO4 close to 0
Temp 79
Ca 460 mg/L (pretty much normal now after the spike in alk)
Alk 18 dKH
Mg I do not have a kit. Should probably be my next purchase.

Should I do water changes to try to bring the alk back down to say below 14 dKH, or shoud I leave the tank alone and see if alk will drop on its own, or should I be doing something else.

My total water volume is about 90 gallons.

Thanks,

José

[josenestor]

I did some quick reading of a few articles linked to this page. Although very informative, I could not find a strategy for normal Ca and very high alk.

I have so far changes 10 gal with only a slight decrease in alk.

Any input would be appreciated.

Thanks,

José

[Randy Holmes-Farley]

My calcium and alkalintiy article discusses all possible scenarios for calcium and alkalinity:

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

In a situation like this, I'd maintain calcium with calcium chloride for a few days to a week or two as alkalinity declines to normal. Then once it is balanced, use a balanced calcium and alkalinity additive going forward.

I wouldn't try to correct it with water changes, and such changes are not necessary to make this correction.

[josenestor]

Thank you Randy,

I actually found your article before reading your reply and stopped the water changes. It was extremely informative on a fairly complicated subject. I recently installed a Ca reactor which I turned off upon the high alk. I was in the process of establishing an alkalinity/pH balance with the reactor when I screwed things up. After reading your article I turned the reactor back on and reduced the CO2.

The alk is now down to 16.8. My pH is 8.12 (daylight) and goes down to about 2.82 at night. I have a daytime refugium (not much algae yet). I am planning on adding a large nightime refugium as well to try to bring the nightime pH up naturally. If this does not work, then perhaps I'll feed kalkwasser in addition to the Ca reactor.

Once again thank you for your reply, I appreciate having someone like you to go to.

Take care,

José

[Randy Holmes-Farley]

and goes down to about 2.82 at night.

Let's hope not. :lol: Your live rock would bubble away in a few minutes (I know you mean 7.82 :D ).

Your plan sounds like a good one. Good luck with it!

[josenestor]

Hi Randy,

Sorry, 7.82 is correct.

Thanks a million!

José

[Randy Holmes-Farley]

You're welcome.

Happy Reefing. :)