high Ph Swing during the day

[Iloverocks10]

Recently my Ph has begun to rise steadily during the daylight hours in my tank it starts at around 8.4 then climbs to 8.6 and drops down when my lights turn off I have recently changed my lighting setup adding a t5 hybrid fixture to my Leds. my only filtration is a filter sock and miracle mud refugium with a kessil h160 that i run at 40% power 24/7 i have tried turning off the fuge light during the hours of the ph rising and it doesnt seem to affect it at all.
ALK 9.8-10
CAL 400-420
MAG 1100-1150
Nitrate and phosphate are nearly undetectable i dont even get a reading on my hannah checker half the time

Is this something i need to be worried about or should i just let it be

 

[itsken37]

Same dude. I have no idea why.

 

[Reef man 89]

This is mine with a Co2 media on skimmer

 

[sunken3]

my swings are similar (but 7.9 - 8.2)... i would be worried if the swings go too low or too high (but i would also ensure your probe is calibrated - not because of the swing, but the actual measurement value). I think it is daylight that affects it the most. I run an ATS at night and that doesnt seem to do much to change the swing.

 

[Iloverocks10]

my swings are similar (but 7.9 - 8.2)... i would be worried if the swings go too low or too high (but i would also ensure your probe is calibrated - not because of the swing, but the actual measurement value). I think it is daylight that affects it the most. I run an ATS at night and that doesnt seem to do much to change the swing.

Probe was calibrated 2 days ago should have mentioned that

 

[sunken3]

i would be very curious how people have figured out how to keep the pH more constant..

 

[sunken3]

Probe was calibrated 2 days ago should have mentioned that

maybe run co2 scrubber only at night.. that could even out the swing.. (not yours though because your pH is already a bit high during the day... i think a co2 scrubber would only raise it more)

 

[Courtney Aldrich]

The pH swing is caused by changes in CO2 levels in your tank. During the day, photosynthesis consumes CO2 resulting in an increase in pH while the pH will drop at night as the algae in your corals and/or refugium produce CO2 by normal respiration (CO2 reacts with water to produce carbonic acid, H2CO3). The pH swings indicate your new T5s are increasing photosynthesis, which is a proxy for good coral growth!

 

[itsken37]

The pH swing is caused by changes in CO2 levels in your tank. During the day, photosynthesis consumes CO2 resulting in an increase in pH while the pH will drop at night as the algae in your corals and/or refugium produce CO2 by normal respiration (CO2 reacts with water to produce carbonic acid, H2CO3). The pH swings indicate your new T5s are increasing photosynthesis, which is a proxy for good coral growth!

now that i think about it that makes so much sense. thanks for the info!

 

[Iloverocks10]

Thanks for the info i knew that was going on i was just more so wondering if 8.6 was to high i also prob need to increase my nutrient levels to match with the elevated ph and alk

 

[Billldg]

I personally feel that 8.6 is to high. I have mine running between 8.14 and 8.4 and that, I fell is the top as ocean water PH is 8.3 on avg. I can't answer on how to lower it as I have been trying to raise it and never looked at how to lower it Maybe @Jay Hemdal can answer that problem.

 

[Ameer214]

That sometimes certain algaes are more easily cured with a complete tear down than trying to fight it. There are some unbeatable strains.

Agree with above. pH increase during the day is a good thing. You can control how much and how little it increases by how much light you give the system. Ideally, the photosynthesis is happening in the corals and not a unwanted algea.

 

[Courtney Aldrich]

To minimize the pH spike during the day you could dose CO2 to the tank using a CO2 cylinder and regulator with a solenoid controlled by your Apex. This is common in planted freshwater aquariums.

Check this out: https://www.co2art.us/collections/complete-kits

Programming Apex: https://forum.neptunesystems.com/showthread.php?19176-programming-solenoid-for-CO2-dosing

 

[Iloverocks10]

To minimize the pH swings you could dose CO2 to the tank using a CO2 cylinder and regulator with a solenoid controlled by your Apex. This is common in planted freshwater aquariums.

If i have to ill go that route i sold my 2 c02 setups recently didnt think id run into this problem

 

[Jay Hemdal Verified Community Expert]

I personally feel that 8.6 is to high. I have mine running between 8.14 and 8.4 and that, I fell is the top as ocean water PH is 8.3 on avg. I can't answer on how to lower it as I have been trying to raise it and never looked at how to lower it Maybe @Jay Hemdal can answer that problem.

8.6 is a very high pH, I wonder though, that there is a testing issue? Buffering in marine aquariums should keep that high of a level from showing up. Certainly, as others have said, the pH swing is a result of CO2 uptake and production between day and night, but this wide of a swing is unexpected.

Jay

 

[Iloverocks10]

8.6 is a very high pH, I wonder though, that there is a testing issue? Buffering in marine aquariums should keep that high of a level from showing up. Certainly, as others have said, the pH swing is a result of CO2 uptake and production between day and night, but this wide of a swing is unexpected.

Jay

I will bring my hannah ph tester from work home and test it vs my apex both have been calibrated recently and ill report back (Hannah Probe comes back the same around 8.5-8.6)

 

[Randy Holmes-Farley Verified Community Expert]

i would be very curious how people have figured out how to keep the pH more constant..

Complete aeration will flatline the pH.

The larger the swing, the less complete is the aeration must be (ignoring time of day effects impacting the CO2 in the air, such as when there's a big party going on, etc.).

Higher alk also reduces the pH swing.

IMO, the swing is not generally the issue, but rather the extremes of the swing.

 

[sunken3]

Complete aeration will flatline the pH.

The larger the swing, the less complete is the aeration must be (ignoring time of day effects impacting the CO2 in the air, such as when there's a big party going on, etc.).

Higher alk also reduces the pH swing.

IMO, the swing is not generally the issue, but rather the extremes of the swing.

i am still baffled by my tank.. I have a 250g with a 40g sump under it.. my protein skimmer is in that sump.. it has a co2 scrubber attached and the airline is pumped in from outside. Additionally, i have another 60g sump outside attached through piping (so no co2 issue there).. plus all of my topoff water and new SW is made outside and piped in.. yet.. i have issues keeping my ph above 8 (7.9 - 8.1) swings...

 

[Iloverocks10]

Complete aeration will flatline the pH.

The larger the swing, the less complete is the aeration must be (ignoring time of day effects impacting the CO2 in the air, such as when there's a big party going on, etc.).

Higher alk also reduces the pH swing.

IMO, the swing is not generally the issue, but rather the extremes of the swing.

Would you say a swing up to 8.6 is of huge concern

 

[Randy Holmes-Farley Verified Community Expert]

No.