PH changes ocean vs. aquarium

[Jonathan Troutt]

me and my brother got into a discussion today about PH swings. I informed him that I was running my fuge on an opposite lighting schedule to help maintain a steady PH throughout the night.

He proceeded to ask me what the ocean does at night. It got me thinking is it just the sheer volume of water that keeps PH in the ocean stable at night or are there swings at night vs the day?

I did a quick google search didn’t find anything super helpful was hoping you fine gentleman and ladies could help out here.

 

[JasonK84]

Interesting topic. I'll follow!

 

[Cjud7982]

Well my first thoughts are that the sheer volume takes care of that. Plus there are waves crashing and very regular currents to manage gas exchange as well as a balanced macro algea ecosystem. And the ocean is being hit by sun at 24/7 just moves around the world lol. I have no real reasoning behind this, but these are just my off the cuff logic. Very interesting thought. Can't wait to see someone who knows the real details.

 

[Jonathan Troutt]

Well my first thoughts are that the sheer volume takes care of that. Plus there are waves crashing and very regular currents to manage gas exchange as well as a balanced macro algea ecosystem. And the ocean is being hit by sun at 24/7 just moves around the world lol. I have no real reasoning behind this, but these are just my off the cuff logic. Very interesting thought. Can't wait to see someone who knows the real details.

My answer was sheer volume and ocean currents and such. We have powerheads and skimmers to provide gas exchange. Kind of similar to waves and ocean currents.

Take the east coast and the west coast. Easy coast is dark before west coast. I doubt the currents are fast enough to carry water that fast from west to east coast within a day.

It’s interesting to me and I’ve spent some time pondering it. I would love to see some PH study done where they monitored reef PH over a 48 hour period.

 

[JimWelsh]

Google "diurnal pH ocean reef".

 

[saintsreturn]

Interesting idea. But i would counter with the ocean is hit 24 hours a day lol.

 

[Larry L]

Google "diurnal pH ocean reef".

Thanks Jim.

Of the couple I looked at, this one shows a noticeable daily fluctuation pattern, but varying less than about 0.05 per day: http://iocwestpac.org/OA1/14 Malaysia_Zulfigar Yasin.pdf

This one doesn't have full day data but shows daily variations of over 0.7 for certain sites (e.g. from 7.85 to 8.55): https://www.researchgate.net/public...d_metabolic_processes_of_a_coral_reef_Okinawa

 

[Jonathan Troutt]

Ok so some place have very little change while others can change almost a whole unit between night and day. Is my interpretations of this data correct?

 

[Subsea]

Interesting idea. But i would counter with the ocean is hit 24 hours a day lol.

In a system with an algae filter on opposite photoperiod, that would be true.

 

[KrisReef]

me and my brother got into a discussion today about PH swings. I informed him that I was running my fuge on an opposite lighting schedule to help maintain a steady PH throughout the night.

He proceeded to ask me what the ocean does at night. It got me thinking is it just the sheer volume of water that keeps PH in the ocean stable at night or are there swings at night vs the day?

I did a quick google search didn’t find anything super helpful was hoping you fine gentleman and ladies could help out here.

Your brother is correct; The ocean does not run a fuge + light at night.

Next time he brings this up, don't admit this but counter; " Thats what the moon is for." (Sorry. )


@JimWelsh provided a nice Google search that links to articles written by scientist funded by global warming concerns. Very helpful information on open ocean measurements, the articles conclusions were funded by global warming concerns, but still the data is there. Thanks for this thread guys. I leant something today already.

 

[Jonathan Troutt]

So while a lower PH at night will not harm things, as long as ph values do not drop to low, It does affect some species. While other species it doesn’t.

Which would give credit to the argument of keeping ph steady at all times.

That being said. Since some reefs seem to experience these fluctuations and some don’t what causes them and why do some reefs not experience a significant change at night?

 

[Subsea]

So while a lower PH at night will not harm things, as long as ph values do not drop to low, It does affect some species. While other species it doesn’t.

Which would give credit to the argument of keeping ph steady at all times.

That being said. Since some reefs seem to experience these fluctuations and some don’t what causes them and why do some reefs not experience a significant change at night?

Only if high alkalinity demand SPS corals are dominate is fluctuating pH an issue.

I use pH fluctuations during lights out as an opportunity for passive buffering & trace mineral addittion using aroggonite substrate.

 

[Jonathan Troutt]

Only if high alkalinity demand SPS corals are dominate is fluctuating pH an issue.

I use pH fluctuations during lights out as an opportunity for passive buffering & trace mineral addittion using aroggonite substrate.

Could you clarify what you mean by passive buffering and trace mineral addition using aroggonite substrate. Want to make sure I understand

 

[Gregg @ ADP]

As always, it depends on what is around the reef.

Reefs that border lagoons, or estuaries, (especially heavily vegetated) probably experience relatively dramatic pH swings, especially at night. Even moreso if there are freshwater streams emptying nearby.

Hypothetical: nighttime, small lagoon with high density of vegetation, heavy rain draining heavily forested areas —> pretty low pH.

Tide goes out, and all of that low pH water goes over the reef. But...it’s very temporary, so the coral probably brushes it off.

 

[Subsea]

Could you clarify what you mean by passive buffering and trace mineral addition using aroggonite substrate. Want to make sure I understand

Aroggonite will begin to dissolve at a pH of 8.05 contributing to carbonate alkalinity, calcium and minor trace minerals. So, when lights go out and pH begins to drop, at a pH of 8.05 aroggonite begins to dissolve as a buffer to dampen further pH drop.

 

[Jonathan Troutt]

Aroggonite will begin to dissolve at a pH of 8.05 contributing to carbonate alkalinity, calcium and minor trace minerals. So, when lights go out and pH begins to drop, at a pH of 8.05 aroggonite begins to dissolve as a buffer to dampen further pH drop.

Ok that is what I was thinking. Thank you

 

[Randy Holmes-Farley]

Aroggonite will begin to dissolve at a pH of 8.05 contributing to carbonate alkalinity, calcium and minor trace minerals. So, when lights go out and pH begins to drop, at a pH of 8.05 aroggonite begins to dissolve as a buffer to dampen further pH drop.

How did you get that 8.05? I think it doesn’t start to dissolve until pH is below 7.8, unless the alk is below normal.

 

[Graffiti Spot]

And how much does it actually buffer the water and deliver trace minerals? I would think very little. I don't think it would be a reason alone to use a sand bed.

 

[Subsea]

@Randy Holmes-Farley

That number was in some articles by Caribsea many moons ago. Having used a 6” dsb for 25 years with a Jaubert Plenum, I can document loss of substrate into bulk water.
Considering that pH in depths of dsb is different than in bulk water, I say aragonite sandbed can buffer a reef tank. Perhaps not SPS dominate.

 

[Subsea]

How did you get that 8.05? I think it doesn’t start to dissolve until pH is below 7.8, unless the alk is below normal.

I read 8.05 in CaribSea article many moons ago. After 25 years with 6” Jaubert Plenum using aragonite, I can document losing aroggonire substrate to bulk water.

Considering chemistry in depths of sand bed to be different than in bulk water, I say that aroggonite .dissolved alkalinity & trace minerals into my bulk water.