Tight pH Swing

[drblank1]

I can control my swing as tight as I want. I can peg my pH at 8.3 with as small of a swing as .1 if I want. I use a CO2 scrubber and an valve/Apex to control scrubbed air intake into my skimmer. I was reading old posts and Randy suggested that a stable pH may be stressful on the reef inhabitant. Is this still a possible thought? If so, what swing should we have?

 

[arking_mark]

A stable pH = more stable parameters = less stress to inhabitants. Link to posts that say otherwise?

 

[arking_mark]

I'm keeping my pH swing +/- 0.03...

 

[Randy Holmes-Farley Verified Community Expert]

I do not recall thinking that stable pH was stressful, but I may have said (and still think) that a low steady pH is more stressful than pH with a daily swing that hits that low but then goes higher.

 

[RobB'z Reef]

maybe that's why the corals are dying in the ocean...that steady 8.3

 

[GarrettT]

I'm keeping my pH swing +/- 0.03...

How are you accomplishing this?

 

[arking_mark]

How are you accomplishing this?

I will preface below with a cavate that there may be little benefit other than accelerated growth and some additional tank stability (which may be very valuable to coral farmers). Many hobbyists are successful with pH between 7.8 and 8.6 and large 0.4 day/night swings. As long as your tank is well aerated and in-home CO2 levels are healthy for humans, you don't really need to worry about pH.

Lessons learned in trying to maintain pH stability

For those interested in maintaining pH stability around +/- 0.05 I have a couple of lessons learned. These are things that I found out on my journey to pH stability. Prior to seeking pH stability my tank pH was consistently around ~7.9. However, much of this journey went on before the tank was...

www.reef2reef.com

Tuning a Skimmer / CO2 Scrubber for pH Control

On my reefing journey, I found Kalkwasse + Skimmer + CO2 Scrubber to be very effective for bringing my pH from 7.8 - 7.9 to 8.26 - 8.36. I guess most people would just leave it at that. However, I wanted to be more efficient with the CO2 scrubbing material so I wanted to implement a...

www.reef2reef.com

 

[drblank1]

I do not recall thinking that stable pH was stressful, but I may have said (and still think) that a low steady pH is more stressful than pH with a daily swing that hits that low but then goes higher.

Acceptable Ph swing?

We try and minimise the Ph swings with reverse cycle lighting and even feeding the skimmer with outside air etc etc. However, what is the range of an acceptable daily Ph swing for SPS/LPS corals?

www.reef2reef.com

Post #2

I think I did not read it correctly. I believe you were indicating that a low constant pH is as or more stressful than a swing within the acceptable ranges. Not sure but if I read that wrong the first time, my apologies.

 

[Randy Holmes-Farley Verified Community Expert]

Acceptable Ph swing?

We try and minimise the Ph swings with reverse cycle lighting and even feeding the skimmer with outside air etc etc. However, what is the range of an acceptable daily Ph swing for SPS/LPS corals?

www.reef2reef.com

Post #2

I think I did not read it correctly. I believe you were indicating that a low constant pH is as or more stressful than a swing within the acceptable ranges. Not sure but if I read that wrong the first time, my apologies.

Yes, the intent was to focus more on the low pH and the time spent at low pH, rather than the swing itself (IMO).

 

[brmc1985]

Yes, the intent was to focus more on the low pH and the time spent at low pH, rather than the swing itself (IMO).

Randy, you would probably know better but don’t coral reefs have similar ph swings on them as well?

 

[Randy Holmes-Farley Verified Community Expert]

Randy, you would probably know better but don’t coral reefs have similar ph swings on them as well?

Corals in lagoons experience substantial pH swings. Corals in more open reefs show less pH swing. Rarely do natural coral areas swing down below pH 7.8.

Here's a bunch of data:

https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.10129

 

[brmc1985]

Corals in lagoons experience substantial pH swings. Corals in more open reefs show less pH swing. Rarely do natural coral areas swing down below pH 7.8.

Here's a bunch of data:

https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.10129

Thanks. I guess my point was that reefs experience swings just like our tanks do. As long as they stay above the 7.8 with .3 swings or so daily that’s not too uncommon from natural reefs. I understand that there are differences between shallow and deeper water reefs but a lot of people maintain tanks with corals from all over the world from different depths and conditions. So I guess where I was going with this is don’t worry about the PH swing as long as you aren’t lower than 7.8 and focus on the parameters that stay relatively stable in the ocean throughout the day like the big 3 and nutrients.
TLDR Don’t focus on PH as long as your minimum is above 7.8 and focus on keeping alk stable.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks. I guess my point was that reefs experience swings just like our tanks do. As long as they stay above the 7.8 with .3 swings or so daily that’s not too uncommon from natural reefs. I understand that there are differences between shallow and deeper water reefs but a lot of people maintain tanks with corals from all over the world from different depths and conditions. So I guess where I was going with this is don’t worry about the PH swing as long as you aren’t lower than 7.8 and focus on the parameters that stay relatively stable in the ocean throughout the day like the big 3 and nutrients.
TLDR Don’t focus on PH as long as your minimum is above 7.8 and focus on keeping alk stable.

Yes, my opinion has been and continues to be that low pH is suboptimal compared to higher pH for hard corals and other calcifying organisms, but that a diurnal pH swing within reasonable limits is not a concern.

 

[GarrettT]

TLDR Don’t focus on PH as long as your minimum is above 7.8 and focus on keeping alk stable.

I’ve found they really go hand in hand. As long as the PH drops the same amount everyday, then the alkalinity consumption should should be rather predictable. With covid, my issue is that our schedules are irregular, which has my PH bouncing around. It’s hard to stabilize Alk when this happens.

 

[Subsea]

Thanks. I guess my point was that reefs experience swings just like our tanks do. As long as they stay above the 7.8 with .3 swings or so daily that’s not too uncommon from natural reefs. I understand that there are differences between shallow and deeper water reefs but a lot of people maintain tanks with corals from all over the world from different depths and conditions. So I guess where I was going with this is don’t worry about the PH swing as long as you aren’t lower than 7.8 and focus on the parameters that stay relatively stable in the ocean throughout the day like the big 3 and nutrients.
TLDR Don’t focus on PH as long as your minimum is above 7.8 and focus on keeping alk stable.

Healthy IndoPacific reefs fluctuate between 8.2 and 7.8. During lights out, low oxygen is much more important than low pH. Considering that I use a calcium reactor and grow softies with mixed inverts like flame scallops & sea apples, I see no advantage forcing higher pH.

 

[Subsea]

I will preface below with a cavate that there may be little benefit other than accelerated growth and some additional tank stability (which may be very valuable to coral farmers). Many hobbyists are successful with pH between 7.8 and 8.6 and large 0.4 day/night swings. As long as your tank is well aerated and in-home CO2 levels are healthy for humans, you don't really need to worry about pH.

Lessons learned in trying to maintain pH stability

For those interested in maintaining pH stability around +/- 0.05 I have a couple of lessons learned. These are things that I found out on my journey to pH stability. Prior to seeking pH stability my tank pH was consistently around ~7.9. However, much of this journey went on before the tank was...

www.reef2reef.com

Tuning a Skimmer / CO2 Scrubber for pH Control

On my reefing journey, I found Kalkwasse + Skimmer + CO2 Scrubber to be very effective for bringing my pH from 7.8 - 7.9 to 8.26 - 8.36. I guess most people would just leave it at that. However, I wanted to be more efficient with the CO2 scrubbing material so I wanted to implement a...

www.reef2reef.com

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