Low pH - Let’s talk about it

[PaulieReef]

Have you tried another device to test pH and when was the last time you calibrated both and how.

I used two different professional AC companies to come and check the air quality. One is a personal friend. They matched close to my co2 monitor in the house.

 

[Randy Holmes-Farley]

I used two different professional AC companies to come and check the air quality. One is a personal friend. They matched close to my co2 monitor in the house.

I think the question was about the pH meter.

With alk at 8.5 dKh and normal CO2 levels, complete aeration with normal air will bring the pH to about 8.1 - 8.2.

 

[DaveC]

I think the question was about the pH meter.

With alk at 8.5 dKh and normal CO2 levels, complete aeration with normal air will bring the pH to about 8.1 - 8.2.

Sorry if this seems obvious, but what is considered normal CO2 levels? I am showing ~650 on the meter right next to me.

 

[Randy Holmes-Farley]

Sorry if this seems obvious, but what is considered normal CO2 levels? I am showing ~650 on the meter right next to me.

Average outdoor CO2 at sea level is presently about 420 ppm.

 

[PaulieReef]

Have you tried another device to test pH and when was the last time you calibrated both and how.

I have used 3 devices to check pH, Neptune double junction pH probe, hannah ph pen and maluakee pH.

Going to recalibrate my pH probe for the tank again for posterity.

 

[PaulieReef]

I think the question was about the pH meter.

With alk at 8.5 dKh and normal CO2 levels, complete aeration with normal air will bring the pH to about 8.1 - 8.2.

Basic question, could my tank not be turned over enough? Currently running 2x Varios6 at about 65%. With my calculated head pressure, it seems I am getting about 900 gph between the two of them so with just my return pump I am getting 2x turn over. I found mix answers on suggested turn over, some said 4, some said 20x.

 

[Troylee]

Welcome to the world of carbon dosing… my alk runs high and I still can’t get my ph up.. I use kalk my huge skimmer pulls from outside also.. the only time I see 8.2-8.4 is if my windows are open all day and then it’s short lived when I close the house down.. 3 people and large dogs in my house.

 

[Randy Holmes-Farley]

Basic question, could my tank not be turned over enough? Currently running 2x Varios6 at about 65%. With my calculated head pressure, it seems I am getting about 900 gph between the two of them so with just my return pump I am getting 2x turn over. I found mix answers on suggested turn over, some said 4, some said 20x.

Easier to test than to estimate:

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

The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.

 

[PaulieReef]

Easier to test than to estimate:

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

The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.

I did this test before and only had a .05 pH change, I however did not note the temp change and let it go for more than an hour, so I will redo this test again this week. I will check the other link as well.

 

[DaveC]

@Randy Holmes-Farley Dang, You had this figured out in 2015

 

[besskurz]

Easier to test than to estimate:

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

The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.

I did finish the aeration test as well.

Outside aeration (before/after)

Indoors aeration (before/after)

@Randy Holmes-Farley, would correct to say that I have too much co2 indoors?

I'm thinking about setting up an air pump outside and bring the airline to the thank.

My second question is:
I have a jaubert bowl, with a lid to control evaporation. The fresh air from outside should be send to inside the water column with an air stone (and accept the mist and some salt creep) or by simply blowing inside the tank would be enough?

Thank you!

 

[Randy Holmes-Farley]

Yes, I’d say indoor CO2 is high.

Blowing over the tank may help, but into a skimmer usually is best.