Low pH - Let’s talk about it

[PaulieReef]

What/if anything am I missing that could be causing low pH? I know chasing numbers isn’t the best but I would like the low range of my pH fall higher for better coral growth.

Water Chemistry:
pH: 7.8-8.0
Alk: 8.5
Calc: 440
Mag: 1400
Salinity: 1.026
Nitrate: 10.8
Phosphate: 0.06
Tank Age: 1y 1 month
Tank Size: 375g
Skimmer: Reef Octopus SRO 5000-ext
Power Heads: 4x Gyre (2x280s on back wall, 2x 350s on sides) very heavy surface agitation
CO2 inside house 450 during the day 800 at night

Currently running Kalk
CO2 Scrubber
Macro Algae (cheato reverse light cycle)
Stop running CarX

Read the other posts and couldn't find what might be causing it.

Only other cause I might relate is dosing NoPox at 30ml a day possibly causing high bacteria population and depletion of o2?

Using NoPox to slowly lower Nitrate. Nitrate is lowering about 1-2 a day. Will be lowering dose until levels out around 2

 

[blaxsun]

NOPOX will definitely tank your pH levels when you use it.

 

[PaulieReef]

NOPOX will definitely tank your pH levels when you use it.

I read up on it before this post and couldnt find it caused any substantial pH drop. Additionally, I had low pH before I started dosing nopox. Highest I have ever gotten my pH was 8.1 and that was heavy kalk dosing which caused my alk to rise to much.

So maybe the answer is more coral for higher alk consumption for more kalk dosing!

 

[spsick]

I suggest finding out what the co2 levels in your home are to check that off the list.

Here is a well regarded basic meter that uses the same sensor as the higher end ones:

 

[PaulieReef]

I suggest finding out what the co2 levels in your home are to check that off the list.

Here is a well regarded basic meter that uses the same sensor as the higher end ones:

Already had it professionally done

CO2 inside house 450 during the day 800 at night

 

[spsick]

Already had it professionally done

CO2 inside house 450 during the day 800 at night

Shoot I missed that in your post but Whoa that’s crazy low! Did you have an air exchanger or something?

What are you using to supply calcium/alkalinity currently?

 

[PaulieReef]

Shoot I missed that in your post but Whoa that’s crazy low! Did you have an air exchanger or something?

What are you using to supply calcium/alkalinity currently?

Nah, just not a well sealed house, its a nice age

Was using CarX, but took it offline because of the low pH a few weeks ago and switched to purely kalk.

 

[blaxsun]

I read up on it before this post and couldnt find it caused any substantial pH drop. Additionally, I had low pH before I started dosing nopox. Highest I have ever gotten my pH was 8.1 and that was heavy kalk dosing which caused my alk to rise to much.

So maybe the answer is more coral for higher alk consumption for more kalk dosing!

I don't have the answer for you, but I can tell you that whenever I dose NOPOX (which isn't that often) I can watch the pH hit in realtime on my Apex. It usually takes a few days after dosing to return to normal levels as well.

I typically see a pH range of between 8.05 to 8.25 most days with +/-0.05 variance. This is without a Co2 scrubber.

 

[PaulieReef]

I don't have the answer for you, but I can tell you that whenever I dose NOPOX (which isn't that often) I can watch the pH hit in realtime on my Apex. It usually takes a few days after dosing to return to normal levels as well.

Yeah, I got mine on a reefdose 4 so I can spread out the dose throughout the day while lights are on.

 

[blaxsun]

Yeah, I got mine on a reefdose 4 so I can spread out the dose throughout the day while lights are on.

That probably mitigates the initial "hit", but the dosing over a day probably has a cumulative effect. I'd stop NOPOX for a week and see what happens with your pH.

 

[PaulieReef]

That probably mitigates the initial "hit", but the dosing over a day probably has a cumulative effect. I'd stop NOPOX for a week and see what happens with your pH.

Mentioned earlier I had this issue before I started dosing nopox as well.

 

[blaxsun]

Mentioned earlier I had this issue before I started dosing nopox as well.

Everyone I know took a big pH hit over the summer with all the smoke from forest fires. This is the first year where this was very noticeable for me.

 

[spsick]

Re: the co2, it may be worth rechecking. I’m in a 100 year old home with mostly old windows and mine is crazy high, 900-100 during the day when wife is at work and 2000ppm in our bedroom at night. The first co2 meter I had did automatic calibration and just reset itself to baseline (400ppm) daily so I was seeing low numbers and not worried but recently got an Aranet4 and it’s obvious why I am also suffering from low pH.

 

[PaulieReef]

Re: the co2, it may be worth rechecking. I’m in a 100 year old home with mostly old windows and mine is crazy high, 900-100 during the day when wife is at work and 2000ppm in our bedroom at night. The first co2 meter I had did automatic calibration and just reset itself to baseline (400ppm) daily so I was seeing low numbers and not worried but recently got an Aranet4 and it’s obvious why I am also suffering from low pH.

I had two professionals come out to test and checked it against my monitor that I bought on Amazon and the readings were very close.

I live in a 2800 sqft house covered in plants with just me and my significant other.

 

[Randy Holmes-Farley Verified Community Expert]

pH is determined mathematically by alkalinity and CO2.

If pH is low and alk is normal, CO2 in the water must be high.

NOPOX lowers pH, both instantly when added due to the acetic acid in it, and later when all the components are metabolized to CO2,

Ways to raise pH typically involve reducing CO2 in the water, and there are many ways.

 

[PaulieReef]

pH is determined mathematically by alkalinity and CO2.

If pH is low and alk is normal, CO2 in the water must be high.

NOPOX lowers pH, both instantly when added due to the acetic acid in it, and later when all the components are metabolized to CO2,

Ways to raise pH typically involve reducing CO2 in the water, and there are many ways.

Outside of a giant skimmer (which I have), running co2 media (which I am using) and heavy surface agitation (which I am also doing), what are the other ways?

 

[Randy Holmes-Farley Verified Community Expert]

Outside of a giant skimmer (which I have), running co2 media (which I am using) and heavy surface agitation (which I am also doing), what are the other ways?

Ultra high pH alk additives when alk is needed, fresher air to the room, and more photosynthesis (e.g., a refugium), and more tank aeration if the room air is not elevated in CO2.

 

[jason2459]

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

 

[FiveGallonSea]

What salt do you use? I use Red Sea Coral Pro since the beginning and I can't get my pH above 7.8-8.0 all these years. I just gave up because everything seems okay

 

[Randy Holmes-Farley Verified Community Expert]

What salt do you use? I use Red Sea Coral Pro since the beginning and I can't get my pH above 7.8-8.0 all these years. I just gave up because everything seems okay

FWIW, pH should have nothing to do with the salt mix, unless it is a type that contains organic matter than may degrade to CO2.