pH keeps dropping- Why? - Page 2

Randy Holmes-Farley · 04/01/2009, 04:44 AM

The Superbuffer would not be my first choice, both because it does not raise pH much and because of the borate in it. Limewater would be the best choice, followed by a high pH two part or baked baking soda.

IMO, pH concerns rise as the pH drops below 8.2, but reefs operate fine for a while. As the pH drops below 7.8 I get much more concerned. A bit lower than that and coral skeletons can begin to dissolve.

These have more:

The "How To" Guide to Reef Aquarium Chemistry for Beginners, Part 3: pH
http://reefkeeping.com/issues/2007-05/rhf/index.php

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

SaltyTX · 04/02/2009, 04:28 PM

well. Question-

Will a nutrient rich tank, undergoing a lot of decomposition (but efficiently to limit nitrates/nitrites/ammonia) destroy the alk/pH readings?

Randy Holmes-Farley · 04/03/2009, 04:57 AM

If nitrate is actually increasing (not just high, but increasing), then that can deplete alkalinity as it rises. If that nitrate is being taken back up into macroalgae, then there is no depletion. I discuss that here:

When Do Calcium and Alkalinity Demand Not Exactly Balance?
http://reefkeeping.com/issues/2004-12/rhf/index.htm

A sulfur denitrator, however, will also deplete alkalinity.

pH is mostly driven by atmospheric CO2, but in tank sources of CO2 also impact it.

SaltyTX · 04/03/2009, 11:23 AM

well Mg levels are 1520ish

Ca is 340, a bit low.

wonderific.

WaterKeeper · 04/03/2009, 11:30 AM

Quote:

Originally posted by SaltyTX
Ok.....I understand the article. And have talked with my wife who deals with aquatic water chemistry (recently published by the way )

Finally, someone who understands Randy but he did need to bring in a ringer.

04/01/2009, 04:44 AM	#26
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	The Superbuffer would not be my first choice, both because it does not raise pH much and because of the borate in it. Limewater would be the best choice, followed by a high pH two part or baked baking soda. IMO, pH concerns rise as the pH drops below 8.2, but reefs operate fine for a while. As the pH drops below 7.8 I get much more concerned. A bit lower than that and coral skeletons can begin to dissolve. These have more: The "How To" Guide to Reef Aquarium Chemistry for Beginners, Part 3: pH http://reefkeeping.com/issues/2007-05/rhf/index.php Low pH: Causes and Cures http://reefkeeping.com/issues/2004-09/rhf/index.htm __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

04/03/2009, 04:57 AM	#28
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	If nitrate is actually increasing (not just high, but increasing), then that can deplete alkalinity as it rises. If that nitrate is being taken back up into macroalgae, then there is no depletion. I discuss that here: When Do Calcium and Alkalinity Demand Not Exactly Balance? http://reefkeeping.com/issues/2004-12/rhf/index.htm A sulfur denitrator, however, will also deplete alkalinity. pH is mostly driven by atmospheric CO2, but in tank sources of CO2 also impact it. __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

04/02/2009, 04:28 PM	#27
SaltyTX Registered Member Join Date: Feb 2009 Location: SC for now.. Posts: 155	well. Question- Will a nutrient rich tank, undergoing a lot of decomposition (but efficiently to limit nitrates/nitrites/ammonia) destroy the alk/pH readings?

04/03/2009, 11:23 AM	#29
SaltyTX Registered Member Join Date: Feb 2009 Location: SC for now.. Posts: 155	well Mg levels are 1520ish Ca is 340, a bit low. wonderific.