Very High ALK... What are the dangers?

[MY120ROCKS]

Hi Randy (and all who read!)

I have an ALK reading of 5.5 meq/L or 15.5 dKH and a calcium reading of 425. I have been using a calcium reactor on a new 120 gal reef. I read your article http://www.advancedaquarist.com/issues/nov2002/chem.htm and am beginning ALK corrections as we speak (Zone 1). I've turned off the CO2 to the reactor (Left the reactor drip though... is that ok?) and will suppliment with calcium until the ALK corrects itself and then resume using the reactor to maintain acceptable levels. My question is are there any specific dangers to corals and fish with ALK levels that high? Fish are doing well... eating and not showing any signs of stress and both my SPS, soft and LPS corals are all ay full polyp extension. Thanks... This is a great forum by the way!

:beer:

Oh, as a side note, if you are wondering how I got the ALK so high. I was adding PH buffer to my top off R/O water... Won't be doing that anymore....

 

[bertoni]

That alkalinity doesn't seem to be high enough to cause any problems. I'd just let it drop own its own. If any animals start to show signs of trouble, some water changes would be the safest way to lower alkalinity.

 

[MY120ROCKS]

<a href=showthread.php?s=&postid=8271250#post8271250 target=_blank>Originally posted</a> by bertoni
That alkalinity doesn't seem to be high enough to cause any problems. I'd just let it drop own its own. If any animals start to show signs of trouble, some water changes would be the safest way to lower alkalinity.

Thank you! Is it OK to just turn off the CO2 only or should I shut down the reactor entirely?

 

[bertoni]

Turning off the CO2 will stop the supplementation, so that should be enough.

 

[Randy Holmes-Farley]

Turning it down to a lower level of CO2 addition will drop alkalinity more slowly (which is OK, IMO), but may allow you to home in on an appropriate long term CO2 addition rate faster, as opposed to on/off changes.

 

[manofcoral]

Question then Randy, I have a high Alk also, but not really worried about it. Anyway, if you turn down the CO2 bubble rate won't the Ca drop also?. Thanks

Paul<><

 

[MY120ROCKS]

I'm planning on manually adding Kent Turbo Calcium to offset the calcium loss while the CO2 is off. Once the ALK drops to my desired point, I will then resume the CO2 bubble to maintain both CA and ALK.

 

[Randy Holmes-Farley]

Question then Randy, I have a high Alk also, but not really worried about it. Anyway, if you turn down the CO2 bubble rate won't the Ca drop also?. Thanks

Yes, but often not enough to be important.

If the alkalinity drops by a full 1 meq/L (2.8 dKH), calcium will only drop by 18-20 ppm.

If there is a drop, the calcium chloride is useful.