PH options

[maff2026]

40 gallon tank, temperature 26c, aragonite, coral rock. Skimmer running, UV power head running and cannister running.
PH is hovering around 8.6 but can't check KH till test kit arrives. If it continues to creep up what are my options? I've turned the air valve off on the powerhead this morning because the skimmer and the powerhead were producing a lot of oxygen but not checked PH since turning it off. Could it have been over oxygenated? If lowering oxygen doesn't lower the PH, would raising the temperature a degree or two be an option? Tank has only been running 5 days with no cycle done yet.

 

[Dread Pirate Dave]

40 gallon tank, temperature 26c, aragonite, coral rock. Skimmer running, UV power head running and cannister running.
PH is hovering around 8.6 but can't check KH till test kit arrives. If it continues to creep up what are my options? I've turned the air valve off on the powerhead this morning because the skimmer and the powerhead were producing a lot of oxygen but not checked PH since turning it off. Could it have been over oxygenated? If lowering oxygen doesn't lower the PH, would raising the temperature a degree or two be an option? Tank has only been running 5 days with no cycle done yet.

What are you checking PH with? Are you dosing anything to increase PH? A tank with less available oxygen isn't the direction I would go.

 

[maff2026]

Testing with NT labs marine ph high range kit but I've got 3 seperate ph electronic testers which usually exactly tally with the NT labs.

 

[maff2026]

And no, i never dose anything

 

[Randy Holmes-Farley]

I think it is HIGHLY unlikely that the pH is actually 8.6 in a tank getting any sort of aeration and not using high pH additives (notably hydroxide).

If somehow it were that high, aeration alone will lower it. But it is also Ok if by some freak circumstance it is real. pH too high is generally not a thing in the absence of hydroxide dosing.

You could try this aeration test (it should drop a lot), but I'd also recalibrate the electronic probes with new pH 7 and 10 buffers, check that it reads them correctly after calibration.

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...

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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.