High Ph - How high is too high?

[AquAttila]

I have a red sea max 250 and seeing the Ph creep up past 8.5 now. I just calibrated my apex Ph probe to make sure there isn't something wrong and seems to be correct. Should this be a concern? what would cause Ph to be this high? I am dosing CarboCalcium (Tropic Marin) but very small amount and Magnesium. Alk is at around 8.2, Calcium 450, Mag 1350.

 

[andrewey]

I wouldn't worry about it. As long as the tank looks happy, don't chase a number. My current tank runs at 8.5 or higher. I ran an experiment and tried to lower it to 8.3 for a few weeks to see if I noticed any changes in growth/behavior. Nothing. So I went back to what it wants to be at

 

[AquAttila]

Appreciate the quick response! it's funny as it has been a challenge to bring Ph up to 8 on my 210 gal but on this RSM it is so high! anyway, I know I have read some time back that anything above 8.45 is dangerous level... this is why I was concerned.

BTW, I do agree with you on chasing numbers. I learned the hard way months ago when I tried to lower Phosphates and killed all my bubble tip anemones. never again.

 

[Randy Holmes-Farley Verified Community Expert]

That pH is fine, and as a general rule, unless you are using high pH additives such as kalkwasser, pH is never too high on its own.

The only caveat to that might be some contrived situation with poor aeration and lots of photosynthesis.

 

[AquAttila]

thanks. yea, it's at 8.6 now and mid-day. I wouldn't' be surprised if it reaches 8.7 by the evening. You mentioned photosynthesis. The only thing I did recently is replaced the T5s, which I do every 12 months anyway.

 

[Dr. Jim]

I have a related question, if you don't mind.....
Would shutting off the skimmer when the pH reaches 8.3-8.5 tend to lower or raise the pH when using:
a) outside air? or,
b) room air?

 

[andrewey]

From my understanding, shutting off the skimmer in both situations would lower the tank's pH in most situation as CO2 builds up from the ambient room and isn't driven off by A) lower CO2 air and B) less gas exchange from a skimmer that's turned off.

 

[Dr. Jim]

From my understanding, shutting off the skimmer in both situations would lower the tank's pH in most situation as CO2 builds up from the ambient room and isn't driven off by A) lower CO2 air and B) less gas exchange from a skimmer that's turned off.

I was thinking that using the skimmer just with room air would tend to lower the pH (once pH is in the 8.3-8.5 range)…. no?

 

[andrewey]

In theory, I agree with your point that once the pH is high enough, drawing from a room with a high enough CO2 concentration should depress the pH and therefore shutting off the skimmer should help to keep the pH elevated. However, in practice, I've found that when my pH is high (8.5) and I'm drawing from room air, if I shut my skimmer off, my pH starts to drop (at least in the first few hours). I'm assuming this is due to the loss of gas exchange, but that's just my guess.

 

[Randy Holmes-Farley Verified Community Expert]

thanks. yea, it's at 8.6 now and mid-day. I wouldn't' be surprised if it reaches 8.7 by the evening. You mentioned photosynthesis. The only thing I did recently is replaced the T5s, which I do every 12 months anyway.

It's not likely acccurate. Don't look for explanations before calibrating the pH meter with new calibration fluids.

In NO case have I seen a reef tank actually hit 8.7 without overdosing high pH additives.

 

[Randy Holmes-Farley Verified Community Expert]

I was thinking that using the skimmer just with room air would tend to lower the pH (once pH is in the 8.3-8.5 range)…. no?

Yes.

 

[Randy Holmes-Farley Verified Community Expert]

I have a related question, if you don't mind.....
Would shutting off the skimmer when the pH reaches 8.3-8.5 tend to lower or raise the pH when using:
a) outside air? or,
b) room air?

lower it with any normal inside or outside air unless the alkalinity is substantially elevated.

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...

www.reefedition.com

Figure 2. The relationship between alkalinity and pH in seawater with normal carbon dioxide levels (black), excess carbon dioxide (purple) and deficient carbon dioxide (blue). The green area represents normal seawater.

 

[Dr. Jim]

Yes.

Randy, just to be clear.....
I believe I didn't word my question properly. It should have been:

I was thinking that using the skimmer just with room air, vs turning the skimmer off, would tend to lower the pH (once pH is in the 8.3-8.5 range)?

You said "Yes".....but after reading your next post, I think you would have said "No" if I worded the question correctly in the first place. Correct?

In other words: If the pH is 8.3-8.5 and you want to lower it, then shutting off a skimmer using room air should help.

However, I tried turning it off today and the pH climbed from 8.33 to 8.37. But since it normally rises during the day it is hard to know if it would have climbed faster or more slowly with the skimmer on (and using room air). (I'm trying to lower it to 8.30)

Thanks for helping.

 

[Randy Holmes-Farley Verified Community Expert]

Randy, just to be clear.....
I believe I didn't word my question properly. It should have been:

I was thinking that using the skimmer just with room air, vs turning the skimmer off, would tend to lower the pH (once pH is in the 8.3-8.5 range)?

Any aeration with normal or high CO2 air will lower the pH when the pH is higher than equilibrium with normal air. 8.3-8.5 fits that description unless the alkalinity is high.

In other words: If the pH is 8.3-8.5 and you want to lower it, then shutting off a skimmer using room air should help.

No, it will not help to shut it off. The skimmer will add CO2 and lower pH.

I saw that myself when I tested with my skimmer offline for a couple of months. My pH rose to 8.35 - 8.55 and stayed higher than normal (I use limewater)

 

[Dr. Jim]

Any aeration with normal or high CO2 air will lower the pH when the pH is higher than equilibrium with normal air. 8.3-8.5 fits that description unless the alkalinity is high.



No, it will not help to shut it off. The skimmer will add CO2 and lower pH.

I saw that myself when I tested with my skimmer offline for a couple of months. My pH rose to 8.35 - 8.55 and stayed higher than normal (I use limewater)

Thank you for clarifying that, Randy. This makes sense because after watching the pH climb from 8.34 to 8.37 today with the skimmer off, it then remained at 8.37 after turning the skimmer back on. (Normally the pH would continue to climb at this time of day).
I appreciate the help...thank you!

 

[wranodj]

I use kalkwasser in my ATO and pH ranges 8.3 - 8.7.

 

[Dav2996]

I have a related question, if you don't mind.....
Would shutting off the skimmer when the pH reaches 8.3-8.5 tend to lower or raise the pH when using:
a) outside air? or,
b) room air?

Dose nopox it will lower your ph. It’s how I control kalk

 

[Randy Holmes-Farley Verified Community Expert]

Dose nopox it will lower your ph. It’s how I control kalk

Yes, it will have a pH lowering effect.

 

[MexiReefer]

That pH is fine, and as a general rule, unless you are using high pH additives such as kalkwasser, pH is never too high on its own.

The only caveat to that might be some contrived situation with poor aeration and lots of photosynthesis.

can you really have too mucho photosynthesis? I also have consistent high pH, and if I lower mi light itensity it decreases and I arrived to the conclusion that it was photosynthesis.

I also have dull coral color (don't we all), can it be related to this "too much photosynthesis?

thanks for any insight

 

[Travv26]

It's not likely acccurate. Don't look for explanations before calibrating the pH meter with new calibration fluids.

In NO case have I seen a reef tank actually hit 8.7 without overdosing high pH additives.

So I know you said before never have ph to high on its own. Now with dosing like kalk to raise your ph when would you say it is to high.

How high of ph would be acceptable without ph additives and how high would have ph would be acceptable with dosing kalk.

I dose kalk to help with my nightly ph drop to try and level out the ph wave. But recently I have started to notice my ph level increasing and hitting a new high after my lights peak time. So nothing is added at this time. Yes my overall ph has increased but my new ph peak is a lot higher