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View Full Version : Randy - am i getting anything out of it?


dreamreefer
01/29/2007, 01:18 PM
I've been dosing kalk and my mix is 2 tsp per gallon. the reservoir is a 20 gal tank with a hooked-in powerhead turn on constantly. my new prop setup does not have too many stonies, a few acros, and a clam...my alk still drops 2dkh everyday, just like the days when i had a tank full of sps and lps in a 70 gal tank. I'm wondering if there are too much carbonic acid that takes it down. i suspect it could be nitrates or phosphates but the tests turn out -ve, did water changes but alk still drops by 2dkh everyday and I top that off with baking soda...im just wondering of my dosing of kalk did anything at all?

Thanks Randy...

Randy Holmes-Farley
01/29/2007, 02:16 PM
I would not stir the limewater after the initial mixing. Such stirring just makes it more likely to be degraded with CO2 that enters the limewater.


I'm not sure I understand the carbonic acid question. Carbonic acid does not reduce alkalinity.
You may just need more than the limewater can give, so a two part in addition to or instead of the limewater is a good way to go.

dreamreefer
01/29/2007, 03:13 PM
well i meant anything that is acidic will lower the ph since alk is a buffer it will be lowered too...I will stop the pump in there and see if that makes a diff. thanks Randy.

ps. i do keep the reservoir airtight tho, you think it will still be a problem?

Randy Holmes-Farley
01/29/2007, 03:20 PM
No, not all acidic things lower alkalinity. In particular, no amount of carbonic acid can lower alkalinity.

If the reservoir is air tight, stirring is less of a concern, but still not necessary.

dreamreefer
01/29/2007, 04:31 PM
thanks for your input Randy...so besides ammonia, nitrite, what else is there is a reef tank to lower the ph? I thought when animals respire, the CO2 released becomes carbonic acid in water and thus, lowers ph, hence lowering the alk since that is the buffer against ph swings? let me know if I need to be cirrected there, thanks!

Randy Holmes-Farley
01/29/2007, 07:10 PM
Ammonia and nitrite do not lower pH. Carbon dioxide is what lowers tank pH, but it does not lower alkalinity.
See this article:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

Randy Holmes-Farley
01/29/2007, 07:23 PM
I show why it is impossible for CO2 to lower alkalinity in this article (near the end):

What is Alkalinity
http://www.advancedaquarist.com/issues/feb2002/chemistry.htm

dreamreefer
01/30/2007, 02:35 AM
thanks for the refernce Randy, i'll read it up...

i took your chemistry quiz twice at different times both times came up apprentice chemist thought i knew something but boy do I have much more to learn! thanks again...

Randy Holmes-Farley
01/30/2007, 08:38 AM
:lol:

Good luck with it. :)