Should I take action? PH at 8.7

[TheDuude]

Over the weekend my PH reached an all time high of 8.75.
Should I be worried and what should I do be doing to being it down?

120 gallon mixed reef
Salinity 35 ppt
Alk 8.0
Cal 400
Mag 1420

I dose 2 part and pH is being check by apex. I just calibrated the probe using Atlas scientific ref solutions both ref solutions 10 and 7 are spot on. Reef is looking otherwise normal.

 

[arking_mark]

Just my 2 cents, but an 8.75 NBS pH seems highly unlikely unless your dosing an additive that drives up pH or something to remove CO2.

What two part are you using?

During the light cycle your pH can certainly peak due to photosynthesis.

Is the 8.75 a peak during your light cycle?

With perfect house CO2, your ppm should be about 400. If you have perfect aeration your pH at 8dKH would be 8.27 NBS.

A photosynthetic jump of ~0.4 pH seems unlikely.

I would troubleshoot pH with a cup aeration test.

How I use a cup aeration test to help pinpoint certain pH issues.

• I do 2 tests. One outside and one next to the tank.
• I run an airstone for about 1 hour and measure pH.
• If the outdoor test isn't around 8.2 NBS, then I know I have a meter or Alk issue...and it's never an Alk issue.
• If the next to tank test is below 8.2 NBS, then I have higher indoor CO2...almost always the case.
• If the next to tank test is higher than the tank, I have an aeration issue or something else that is driving down pH...it's almost never something else unless I'm dosing something that lowers pH.
• If the next to tank test is lower than the tank but not at desired levels, then I need to look at my pH management setup.

 

[TheDuude]

I dose fritz 2 part, fritz mag, and a very low dose of Nopox (3ml) daily.

Dosing nothing else.

I will try the cup test tonight. I always thought more aeration would cause higher pH

 

[arking_mark]

I dose fritz 2 part, fritz mag, and a very low dose of Nopox (3ml) daily.

Dosing nothing else.

I will try the cup test tonight. I always thought more aeration would cause higher pH

More aeration drives CO2 to air CO2 equilibrium in the tank.

Fritz RPM Alk is deionized water, Sodium bicarbonate, Sodium carbonate which should have some pH boost. How much and often are you dosing?

 

[ylreefer]

That seem awfully high indeed.
If it were me I'd be first calibrating my PH probe with two ranges of solution. Just to rule that out.

Or even better replace it if its a few years old. Not to expensive considering.

I'd try this before attempting to add anything to lower PH. Just my 2 cents

 

[Randy Holmes-Farley]

I agree that the pH is extremely unlikely to be accurate and I would take no action more aggressive than aeration until you recalibrate the pH meter.

 

[Acros]

Is your ph probe upstream or downstream from your dosing line? I have read that downstream could interfere with ph readings.

 

[TheDuude]

Just calibrated last night using two NON expired reference solutions from Atlas scientific. 7 ph and 10. Double checking the refs after calibration and probe appears to be spot on. Probe is less than a year old.

Checked against another cheaper handheld I have and was correlating with the apex. This morning PH is 8.55. if it follows the same trend as yesterday it will top off near 8.8.

 

[TheDuude]

More aeration drives CO2 to air CO2 equilibrium in the tank.

Fritz RPM Alk is deionized water, Sodium bicarbonate, Sodium carbonate which should have some pH boost. How much and often are you dosing?

Two separate doses of 8 ml. One at 6 am one at noon. Alk has been pretty stable for a couple months.

 

[Randy Holmes-Farley]

Just calibrated last night using two NON expired reference solutions from Atlas scientific. 7 ph and 10. Double checking the refs after calibration and probe appears to be spot on. Probe is less than a year old.

Checked against another cheaper handheld I have and was correlating with the apex. This morning PH is 8.55. if it follows the same trend as yesterday it will top off near 8.8.

I still do not believe it is accurate. It would be the single highest correct pH that I have seen out of thousands posted, and I think magnesium hydroxide would be precipitating.

That said, if the pH is high and alkalinity is normal, simple aeration will bring it down.

Try this aeration test (indoor air only) to see how much it comes down:

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.

 

[TheDuude]

I will be doing the aeration test when I get home from work this evening. Also going to stop and get another manual pH test if I can.

Could my source well water have anything to do with it? I am on well water with very high minerals and iron. Incoming from my well water is 750 to 800 ppm. After RO it gets down to around 12 ppm and I swap my DI once I start hitting 3 ppm post DI

 

[TheDuude]

Also,

Is it possible the pH probe is the issue even though it is reading accurately in the reference solution? I even tried measuring pH in a glass outside of sumo to make sure this wasn't em interference or something similar.

 

[Randy Holmes-Farley]

The only things that matter to pH are alkalinity and CO2 (and to a small extent, salinity). So the well water is not an issue.

 

[arking_mark]

I will be doing the aeration test when I get home from work this evening. Also going to stop and get another manual pH test if I can.

Could my source well water have anything to do with it? I am on well water with very high minerals and iron. Incoming from my well water is 750 to 800 ppm. After RO it gets down to around 12 ppm and I swap my DI once I start hitting 3 ppm post DI

I'm on well water as well. RODI does a decent job and wouldn't affect pH.

 

[TheDuude]

Apex is already reporting pH of 8.62 and I won't be home for another 3 hours or so. At what point does high pH become dangerous for my corals and fish?

I'll be getting another pH test for reference on the way home

 

[Randy Holmes-Farley]

Apex is already reporting pH of 8.62 and I won't be home for another 3 hours or so. At what point does high pH become dangerous for my corals and fish?

I'll be getting another pH test for reference on the way home

I do not know what pH limit is a health concern, but I do not believe it is that high.

Folks run into precipitation events before organisms seem to suffer, and that typically happens from dosing very high pH additives.

 

[TheDuude]

I do not know what pH limit is a health concern, but I do not believe it is that high.

Folks run into precipitation events before organisms seem to suffer, and that typically happens from dosing very high pH additives.

Ok thanks for the reassurance.. it's got me a bit worried. I will try and get some more data tonight

 

[TheDuude]

Update: bad probe was the issue. Strange that it seemed to calibrate and read the reference solutions correctly. Swapped out the probe and things are back to normal with PH at 8.3

Thanks all for the help

 

[Randy Holmes-Farley]

Update: bad probe was the issue. Strange that it seemed to calibrate and read the reference solutions correctly. Swapped out the probe and things are back to normal with PH at 8.3

Thanks all for the help

THanks for the update.

Happy Reefing.

 

[arking_mark]

Update: bad probe was the issue. Strange that it seemed to calibrate and read the reference solutions correctly. Swapped out the probe and things are back to normal with PH at 8.3

Thanks all for the help

I figured as much as well. One of my tenants in the hobby is to triple-check before you believe any observations or make any changes to your tank. Our hobby-level testing equipment is more ballpark #s than people usually think. I see so many threads of reefers making unnecessary adjustments or reacting to these #s. In most situations, even if a # is out of wack, you never want to make quick changes to fix the situation. Another tenant...nothing good happens fast in a reef tank. Then the safest course of action for most situations is normally larger water changes and GAC.

I've collected 12 tenants so far...

The 12 Commandments of Reef Keeping

Nothing good happens fast in a reef tank Triple-check before you believe any observations or make any changes to your tank Only make one change at a time in your reef tank Use the right tool for the right job Only dose what you can test for Don't chase #s, chase stability. When altering the...

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