PH fluctuation range

[Night Reefer]

What is an acceptable ph fluctuation range in a 24 hour period for reef tank?

 

[Crabs McJones]

Check out this article by @Randy Holmes-Farley on the subject. Good read

 

[Reeferdood]

Opinions will vary but mine goes from 7.95 to 8.16 on average every day.

 

[Randy Holmes-Farley]

What is an acceptable ph fluctuation range in a 24 hour period for reef tank?

Let's try the reverse too. What are you observing for yours? IMO, the bottom and peak is more important than the size of the range, but a very high range indicates poor aeration.

 

[Night Reefer]

7.8 - 8.0 with c02 scrubber sometimes a bit higher, 7.6 - 7.8 without sometimes lower

 

[Bigfudge]

7.8 - 8.0 with c02 scrubber sometimes a bit higher, 7.6 - 7.8 without sometimes lower

Basically the same as me. My ranges from 7.6 to 7.8 without co2 scrubber. With I get swings from 7.8 to about 8.1 or so.

I’m just trying to not chase pH anymore and have just told myself “it is what it is” and hope for the best. Even with my windows open it doesn’t really fluctuate more than that.

 

[Night Reefer]

Yea I noticed that once I raised the ph my corals stated growing. This is what is making me try

 

[Reeferdood]

Have you considered running an airline outside?
I had to do it and I haven’t been bothered by lower pH since..

 

[Randy Holmes-Farley]

7.8 - 8.0 with c02 scrubber sometimes a bit higher, 7.6 - 7.8 without sometimes lower

If thst is accurate, the pH bottom at 7.6 is a substantial concern. When you bring that up to 7.8, I think it is better.

This has more:

pH And The Reef Aquarium
http://www.reefedition.com/ph-and-the-reef-aquarium/

The Daily pH Swing

One of the first things that aquarists who measure pH notice is that the pH changes from day to night in coral reef aquaria. This diurnal (daily) change in pH in reef aquaria occurs because of the biological processes of photosynthesis and respiration. Photosynthesis is the process whereby organisms convert carbon dioxide and water into carbohydrate and oxygen. So there is a net consumption of carbon dioxide during the day. This causes many aquaria to become deficient in CO2 during the day, raising their pH.

Likewise, all organisms also carry out the process of respiration, which converts carbohydrates back into energy. In the net sense, it is the opposite of photosynthesis, producing carbon dioxide and reducing pH. This process is happening continuously in reef aquaria, but is most evident at night when photosynthesis is not pushing pH upward.

The net effect of these processes is that pH rises during the day and drops at night in most reef aquaria. This change varies from less than a tenth of a pH unit, to more than 0.5 pH units in typical aquaria. Complete aeration of the aquarium’s water will entirely prevent this diurnal pH swing, by driving out any excess carbon dioxide or absorbing carbon dioxide when deficient (assuming the carbon dioxide levels in the home air are steady). In practice, equilibration of carbon dioxide by aeration is difficult, and this goal is not often attained. Consequently, the pH does change between day and night.

Higher alkalinity implies more bicarbonate and carbonate in the water, and together these serve to buffer the water against pH changes (that is, they resist the change in pH as additional acids or bases are added). So the higher the alkalinity, the lower the diurnal pH swing. Also, the higher the pH, the more effective is the buffering provided by bicarbonate and carbonate in seawater (up to about pH 9), so the higher the average pH, the smaller the diurnal swing. Additional chemicals in the water also help to reduce the pH swing; borate, for example, buffers against pH changes.

With that all said, however, I do not believe that the actual change in pH each day is particularly important. I won’t go into the reasoning behind this claim here, other than stating that it is my opinion, based on my understanding of how most organisms control their internal pH, but I do not believe that diurnal pH changes that stay within the range of pH 7.8 to 8.5 are particularly stressful to most reef organisms. That is, these changes are no more stressful than being at the same pH all day. A constant pH of 7.9 may be worse for many organisms than a pH that varies from 8.0 to 8.5 each day. Of course, if the diurnal swing takes the pH outside of this range, i.e., below 7.8 or above 8.5, then certain processes take place that should be corrected, as detailed below.

 

[Night Reefer]

Randy great write up. I live in south Florida need I say more. I might be able to run a line in the attic and then outside but my concern is the temps in the attic is over 100 in the summers which the line needed a to run through about 40 feet. Then to the outside air. I am afraid after a all day job of getting this done my tank temps will rise. I know it’s the co2 because when I went on vacation for a week I watched hit almost 8. Iam a family of 3 along with 2 of each birds, dogs and cats. A frigin zoo. When I went on vacation the dogs and birds were not there just the cats. My son came every day to feed them and left. I found a thread which used the scrubber but hooked the intake to the skimmer cup. This seems to have limited the fluctuation and made the lime last longer. I will give it a try and report back. To readdress the subject what is the max fluctuation on the ph for a reef tank?

 

[Reeferdood]

Randy great write up. I live in south Florida need I say more. I might be able to run a line in the attic and then outside but my concern is the temps in the attic is over 100 in the summers which the line needed a to run through about 40 feet. Then to the outside air. I am afraid after a all day job of getting this done my tank temps will rise. I know it’s the co2 because when I went on vacation for a week I watched hit almost 8. Iam a family of 3 along with 2 of each birds, dogs and cats. A frigin zoo. When I went on vacation the dogs and birds were not there just the cats. My son came every day to feed them and left. I found a thread which used the scrubber but hooked the intake to the skimmer cup. This seems to have limited the fluctuation and made the lime last longer. I will give it a try and report back. To readdress the subject what is the max fluctuation on the ph for a reef tank?

My airline comes from the attic and it is blazing up there.. makes a very little difference in the overall temp...

 

[Night Reefer]

What temps do you run outside during August. We hit 90 plus everyday unless it rains for most of the day

 

[Reeferdood]

What temps do you run outside during August. We hit 90 plus everyday unless it rains for most of the day

I’m in Florida too..[emoji6]