Ph Issues

[chrispol]

I have constantly been having low ph, 7.95 as we speak.7.8 at night, I have tried different ph meters and recalibration, and even test kits.
200G Mixed reef with a sand bed.

Alk 12.4 CA 418 Mg 1381

 

[Spare time]

What do you dose for alk? Do you have a refugium or skimmer (or both)? Does your tank have good surface agitation? Does much fresh air get to the tank?

 

[Mr. Mojo Rising]

its normal in aquariums that ph goes down at night, and back up at daylight hours. My ph is 7.9 at night and 8.1 during the day.

 

[arking_mark]

I have constantly been having low ph, 7.95 as we speak.7.8 at night, I have tried different ph meters and recalibration, and even test kits.
200G Mixed reef with a sand bed.

Alk 12.4 CA 418 Mg 1381

Unlikely that your pH drops that low...you'd have to have over 2000pm CO2 in the house or poor tank aeration.

The best way to assess pH issues is to do a cup aeration test...

Lessons learned in trying to maintain pH stability

For those interested in maintaining pH stability around +/- 0.05 I have a couple of lessons learned. These are things that I found out on my journey to pH stability. Prior to seeking pH stability my tank pH was consistently around ~7.9. However, much of this journey went on before the tank was...

www.reef2reef.com

 

[chrispol]

What do you dose for alk? Do you have a refugium or skimmer (or both)? Does your tank have good surface agitation? Does much fresh air get to the tank?

I am using fauna marine balling, I have The Tunze DOC 9430 skimmer, the surface is agitated but has no surface-breaking flow,

 

[chrispol]

I do hit 8 sometimes.

 

[Spare time]

I am using fauna marine balling, I have The Tunze DOC 9430 skimmer, the surface is agitated but has no surface-breaking flow,

You could try a CO2 scrubber. This would probably be the most effective and won't mess with your dosing regiment.

If you have room, you could try a refugium.

You could also try something like Kalkwasser for dosing.

 

[chrispol]

You could try a CO2 scrubber. This would probably be the most effective and won't mess with your dosing regiment.

If you have room, you could try a refugium.

You could also try something like Kalkwasser for dosing.

Kalk will raise my Alk and Ca though right? So I would have to turn those off?

 

[Randy Holmes-Farley Verified Community Expert]

Kalk will raise my Alk and Ca though right? So I would have to turn those off?

What exactly are you dosing and how much?

 

[A;exr54]

My PH also goes up and down.
Also noticed it went up to 8.4 while we were all away for the weekend.
Usually it spikes at 8.2 when we’re all home.

My tank gets fresh air directly from outside using an air pump outside to an airstone in the fuge.

What I notice is a lot of the readings has to do with what’s also going on it the house the tank is in

 

[arking_mark]

Kalk will raise my Alk and Ca though right? So I would have to turn those off?

Best way to assess your pH is with a cup aeration test.

I will preface below with a cavate that there may be little benefit other than accelerated growth and some additional tank stability (which may be very valuable to coral farmers). Many hobbyists are successful with pH between 7.8 and 8.6 and large 0.4 day/night swings. As long as your tank is well aerated and in-home CO2 levels are healthy for humans, you don't really need to worry about pH.

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.

In my case, I use Kalk dosing, refugium, and a CO2/Skimmer for pH control.

Kalk provides balanced Alk/Ca with a pH boost. Getting the most out of Kalkwasser basically requires you to use it to your evaporation limit. Generally speaking, this is usually somewhere around 1% for most aquariums. This amount of Kalkwasser will replace ~1dKH worth of Alk and a comparable amount of Ca. This is why most tanks require a supplemental Ca/Kalk dosing. From a pH perspective, this amount of Kalkwasser will raise pH by about 0.6 NBS. I have found that a continuous drip of Kalkwasser raises my average pH by about 0.1 NBS.

A reverse light-schedule refugium will provide a pH boost at night though macroalgae photosynthesis. (During the regular light schedule your photosynthetic organisms provide a boost.) I have found this to be a relatively small boost. Maybe around 0.05.

Using a very oversized CO2 scrubbed Skimmer, I can overcome my higher house CO2 aeration occurring from powerheads and return pumps and gain an additional 0.2 NBS bump.

 

[Spare time]

Kalk will raise my Alk and Ca though right? So I would have to turn those off?

Yes it would be an alternative to your current dosing regime

 

[arking_mark]

Yes it would be an alternative to your current dosing regime

It may be in addition depending on your Ca/Alk consumption. You can only dose Kalkwasser to your evaporation rate...~1% or about 1dKH.