What is ‘stable’ pH?

[ClownSchool]

Five months ago, I had a 55 gallon mixed reef tank with a canister filter and my pH was tested using a Hanna meter.
I read it was best to test in the evenings, at the end of the photo cycle, and my tests consistently read just above 8.2.
BUT….since I moved everything over to a RedSea 350 with a sump, 90~ gallon total volume, and an Apex pH probe, I’ve had a problem keeping it above 8.0, and my lows are surprisingly low.
I use EVS two-part with the DOS and add 2ml of Kalkwasser in R/O every morning.

Does anyone have any advice on raising pH?
And,
What should a healthy tank’s pH swing be over 24 hours?
(The most recent dip in pH may have been due to using Aiptasia F)

 

[ScubaFish802]

I have been looking into a CO2 Scrubber - there is a good thread pinned in the DIY forum - and people report at least a .2 - . 3 bump it seems

 

[ScubaFish802]

An Easy Way to Increase Your Tank's pH with a CO2 Scrubber

A common issue among aquariasts is that their tank has a lower than desired pH. Many tanks commonly dip to a pH of 7.8 or even lower at night. Although, to the best of our knowledge, this isn't low enough to harm the inhabitants of your aquarium, it does slow down the growth of your corals...

www.reef2reef.com

 

[thatmanMIKEson]

Five months ago, I had a 55 gallon mixed reef tank with a canister filter and my pH was tested using a Hanna meter.
I read it was best to test in the evenings, at the end of the photo cycle, and my tests consistently read just above 8.2.
BUT….since I moved everything over to a RedSea 350 with a sump, 90~ gallon total volume, and an Apex pH probe, I’ve had a problem keeping it above 8.0, and my lows are surprisingly low.
I use EVS two-part with the DOS and add 2ml of Kalkwasser in R/O every morning.

Does anyone have any advice on raising pH?
And,
What should a healthy tank’s pH swing be over 24 hours?
(The most recent dip in pH may have been due to using Aiptasia F)

I'm jealous, your pH looks better than mine!

 

[takoarm8]

Mine does the same.

 

[vetteguy53081]

Five months ago, I had a 55 gallon mixed reef tank with a canister filter and my pH was tested using a Hanna meter.
I read it was best to test in the evenings, at the end of the photo cycle, and my tests consistently read just above 8.2.
BUT….since I moved everything over to a RedSea 350 with a sump, 90~ gallon total volume, and an Apex pH probe, I’ve had a problem keeping it above 8.0, and my lows are surprisingly low.
I use EVS two-part with the DOS and add 2ml of Kalkwasser in R/O every morning.

Does anyone have any advice on raising pH?
And,
What should a healthy tank’s pH swing be over 24 hours?
(The most recent dip in pH may have been due to using Aiptasia F)

Im at 7.9-8.2 and not unusual to drop at lights off. Generally ph drops when circulation or ventilation in the room is poor . Yes CO2 scrubber is one method for increase best attached to a Protein skimmer . Macro algae also helps with increase as it absorbs co2 and also increasing aeration with air stone helps.
I personally add a little baking soda to the sump and helps maintain my level

 

[c_healy]

Mine use to top out at 8 until I added a diy co2 scrubber to my skimmer. I used an old brs reactor and changed the fittings to 1/4 and ran to line to the skimmer intake

 

[thatmanMIKEson]

Mine use to top out at 8 until I added a diy co2 scrubber to my skimmer. I used an old brs reactor and changed the fittings to 1/4 and ran to line to the skimmer intake

look at your weekend low! Did you have a party

 

[c_healy]

look at your weekend low! Did you have a party

Lol. No. That’s probably when I was using the probe to check something else.

 

[thatmanMIKEson]

Lol. No. That’s probably when I was using the probe to check something else.

I have weekend lows too you know, just not this weeked...

 

[ClownSchool]

Im at 7.9-8.2 and not unusual to drop at lights off. Generally ph drops when circulation or ventilation in the room is poor . Yes CO2 scrubber is one method for increase best attached to a Protein skimmer . Macro algae also helps with increase as it absorbs co2 and also increasing aeration with air stone helps.
I personally add a little baking soda to the sump and helps maintain my level

Do I bake the baking soda to make soda ash, or use straight, untreated baking soda?

 

[vetteguy53081]

Do I bake the baking soda to make soda ash, or use straight, untreated baking soda?

I use straight from box

 

[Randy Holmes-Farley Verified Community Expert]

Does anyone have any advice on raising pH?
And,
What should a healthy tank’s pH swing be over 24 hours?
(The most recent dip in pH may have been due to using Aiptasia F)

You have several different sorts of questions here.

There are lots of good ways to raise pH. More photosynthesis, fresher air to the room, more aeration with low CO2 air (outside air, scrubbed air, etc.), high pH alk additives.

Higher pH does not necessarily mean more stable pH.

The pH swing mostly comes from photosynthesis using CO2 during the day and respiration producing CO2 24/7.

What is healthy is a very complicated question. A big pH swing indicates a lot of photosynthesis and thus might be a sign of health. It is also a sign of lower aeration, as perfect aeration with air that has a fixed CO2 level will be unchanging 24/7.

Lower pH may help some organisms (such as some organisms that get CO2 from the water) and hurt others (certain hard corals may grow more slowly).

Higher pH may also help some organisms and hurt others for the same reason.

A stable pH may not be better for any organisms that a pH that moves day to night.

IMO, the main concern with pH is the low end. Preventing pH from dropping below about 7.8 is beneficial.

 

[arking_mark]

A missing component is the inaccuracies of our hobby grade pH measurements. Our pH probes are generally worse than +/- 0.1 for pH. So at best, with a freshly expertly calibrated probe, you should look at your readings with with +/- 0.1. Other measurement tests may be worse.

 

[Superd513]

Mine does the same.

I wish I had a controller

 

[killer2001]

I don't like to rely too much on my pH probe so I bought a co2 monitor for the fish room. Anytime I test for alkalinity I'll just use the equilibrium pH calculator on hamzasreef.com to give me an idea of where pH is at. My reverse light schedule refugium + skimmer + surface agitation from return pump keeps my water well aerated and my pH only fluctuates about 0.1 from what I've recorded (in a 24h period).

Equilibrium pH Calculator

Aquarium calculator; Estimate the equilibrium pH of your aquarium assuming it is thoroughly aerated.

www.hamzasreef.com

 

[Uncle99]

Two different measuring devices, two numbers.
Both just fine.

 

[Randy Holmes-Farley Verified Community Expert]

I don't like to rely too much on my pH probe so I bought a co2 monitor for the fish room. Anytime I test for alkalinity I'll just use the equilibrium pH calculator on hamzasreef.com to give me an idea of where pH is at. My reverse light schedule refugium + skimmer + surface agitation from return pump keeps my water well aerated and my pH only fluctuates about 0.1 from what I've recorded (in a 24h period).

Equilibrium pH Calculator

Aquarium calculator; Estimate the equilibrium pH of your aquarium assuming it is thoroughly aerated.

www.hamzasreef.com

IMO, that procedure is giving values that do not reflect what is happening in the aquarium water.

It may be a useful guide of what could happen with complete aeration, but I don't see the value in assuming complete aeration.

 

[Superd513]

My tank was at 8.2 for the 3 weeks it’s been up. Then I bought reef roids and feed my corals and it went to 7.8. And a 50% water change didn’t even fix it. There must be another variable that I’m overlooking. I buy my water from LFS they use Brightwell and they had a problem with a valve getting turned on by accident and the salinity went down to 1.020. They claim they have fixed it but I believe their numbers are still off. My oh is still at 7.8. Will another water change bring it back up??? If I use my own mix ??

 

[Randy Holmes-Farley Verified Community Expert]

My tank was at 8.2 for the 3 weeks it’s been up. Then I bought reef roids and feed my corals and it went to 7.8. And a 50% water change didn’t even fix it. There must be another variable that I’m overlooking. I buy my water from LFS they use Brightwell and they had a problem with a valve getting turned on by accident and the salinity went down to 1.020. They claim they have fixed it but I believe their numbers are still off. My oh is still at 7.8. Will another water change bring it back up??? If I use my own mix ??

Water changes are not typically useful for pH issues.

pH is determined ONLY by the alkalinity and the CO2 level in the water.

The CO2 level is dominated by the CO2 level in the room air, the degree of aeration, and the balanced of photosynthesis (uses CO2) and respiration (forms CO2) in the aquarium.

I do not think different foods are likely to impact pH in a big way, and think it most likely the drop you saw was coincidental with the reef roid use. More food in general may tend to lower pH as it is metabolized to CO2, and more nutrients in the food might spur growth of photosynthetic organisms such as algae or corals that may drive up pH a bit through more photosynthesis.