PH of 7.7?

[Floyd-]

Im still new to the reefing stuff so now im really looking into water parameters.
I was concerned that my PH was 7.7 when checked with a Hanna checker.
This is on a JBJ45 AIO tank with 3 fish bit of various coral. I have a tiny skimmer on there but im debating taking it out because it doesnt catch much and just overflows all the time. Alk was at 7.2 the other day I tested. Water temp in the tank sadly is a bit high 81-82f most the day (FL temps)

 

[blaxsun]

Ph will fluctuate during the day, so you may want to test during mid afternoon as well.

 

[mdb_talon]

Do you have a lid on the tank? It could help explain a lower ph and the higher temp.

 

[Randy Holmes-Farley Verified Community Expert]

How are you measuring pH?

 

[Floyd-]

Ph will fluctuate during the day, so you may want to test during mid afternoon as well.

This reading (7.7) was at almost noon

Do you have a lid on the tank? It could help explain a lower ph and the higher temp.

Yes its the solid glass lid that came with the tank.

How are you measuring pH?

With a Hanna checker

 

[Randy Holmes-Farley Verified Community Expert]

This reading (7.7) was at almost noon

Yes its the solid glass lid that came with the tank.

With a Hanna checker

Did you do a two point calibration before using it?

If accurate, there is excessive CO2 in the water, and is low enough that I would try to raise it.

FWIW, this article details a variety of ways to increase pH:

pH and the Reef Aquarium - REEFEDITION

by Randy Holmes-Farley For many aquarists, pH is not something that they have much experience with aside from their aquarium. For many, pH is almost a black box measurement: something to be considered, but whose physical meaning makes little sense to them. This article will Read more here...

www.reefedition.com

 

[mdb_talon]

Yes its the solid glass lid that came with the tank.

A glass lid is nice to limit evap...but thay also limits air exchange which can depress ph and keep temps higher

 

[TastesLikeChicken]

I would focus on increasing your alk first (to about 9 or 10 and do it slowly over several days to weeks) and then see if your pH improves. Even if you correct pH and alk is low, the pH will drop again.

 

[Randy Holmes-Farley Verified Community Expert]

I would focus on increasing your alk first (to about 9 or 10 and do it slowly over several days to weeks) and then see if your pH improves. Even if you correct pH and alk is low, the pH will drop again.

An alkalinity of 7.2 dKH is not low, and is not a cause of low pH. An alk of 7.2 dKH is higher than the ocean at 35 ppt salinity, and that has a pH above 8.1 at normal CO2 levels.

 

[TastesLikeChicken]

An alkalinity of 7.2 dKH is not low, and is not a cause of low pH. An alk of 7.2 dKH is higher than the ocean at 35 ppt salinity, and that has a pH above 8.1 at normal CO2 levels.

Yes. The ocean has alk of 7. But that is a large volume environment, so the buffering capacity is maintained. In the small volume of an aquarium, an alk of 7 would not allow for much buffering capacity in the setting of acidic loads like CO2. Therefore a higher alk is preferable to maintain a safety net with respect to the buffering capacity and maintenance of pH.

 

[Randy Holmes-Farley Verified Community Expert]

Yes. The ocean has alk of 7. But that is a large volume environment, so the buffering capacity is maintained. In the small volume of an aquarium, an alk of 7 would not allow for much buffering capacity in the setting of acidic loads like CO2. Therefore a higher alk is preferable to maintain a safety net with respect to the buffering capacity and maintenance of pH.

I do agree higher alkalinity at the same CO2 level will result in a somewhat higher pH, and if the CO2 level increases later, higher alk will buffer against the pH drop more.

But it is misleading to suggest, as you did, that "Even if you correct pH and alk is low, the pH will drop again."

If he corrects pH in most of the best ways, such as by bringing in fresher air to the room or lower CO2 air to his skimmer, or removes CO2 by using high pH alk additives every day, it will not "drop again".

 

[TastesLikeChicken]

I do agree higher alkalinity at the same CO2 level will result in a somewhat higher pH, and if the CO2 level increases later, higher alk will buffer against the pH drop more.

But it is misleading to suggest, as you did, that "Even if you correct pH and alk is low, the pH will drop again."

If he corrects pH in most of the best ways, such as by bringing in fresher air to the room or lower CO2 air to his skimmer, or removes CO2 by using high pH alk additives every day, it will not "drop again".

Your correct. I probably should have said the pH MAY drop again.

 

[Floyd-]

Did you do a two point calibration before using it?

It has been calibrated with a two point. I do not know the last time it was calibrated. Ill re-calibrate again tonight and see if its off.

A glass lid is nice to limit evap...but thay also limits air exchange which can depress ph and keep temps higher

I have had it pushed back maybe 3 inches to help. This tank doesnt evap much at all. My 5 gallon ATO might last a month before a refill.

 

[Floyd-]

Recalibrated and at 6pm with windows open I got 7.9PH.
Its a start. Also recalibrated my salinity/temp meter and found out that im also at 1.023 instead of 1.025 where it was.