View Full Version : No caulerpa = Higher pH

01/15/2010, 06:56 PM
What do you think?

I have removed the caulerpa I had in my fuge about three days ago and since then my pH has read in 8.10 - 8.15. Before the average was 7.8 - 7.9.

01/15/2010, 07:33 PM
That certainly seems odd. The weather has changed in your area recently, so maybe some other factors around the tank like room heating or ventilation could have influenced the ph.
Anyway, that doesn't appear to be an unusual swing for some systems but it's a good idea to watch. Try to take your readings at the same times each day and log the results.

01/15/2010, 07:48 PM
It is odd, but ventilation in the room hasn't changed. My pH is measure by a probe and my pH doesn't really swing much. Ever since I started observing pH on my controller it has always been in the range 7.6-7.9, hardly ever has it been about 8. But in the last 2 or 4 days it has consistently stayed above 8.1.

01/15/2010, 09:05 PM
You removed all of it?


01/15/2010, 09:13 PM
plants exhale co2 at night and pH of tank is also lower at night, maybe that is causing the low pH average.

01/15/2010, 09:40 PM
You removed all of it?


All of it. No macro algae in the fuge section.

plants exhale co2 at night and pH of tank is also lower at night, maybe that is causing the low pH average.

That makes sense. Then if they inhale co2 during the day why the higher pH during the day since I removed the macro algae?

01/15/2010, 09:59 PM
Is it possible that you removed a lot of detritus with your macroalgae; decaying detritus tends to lower pH?

Randy Holmes-Farley
01/16/2010, 08:24 AM
I see no reason for the higher daytime pH based on the Caulerpa removal, but it may be something else, as several people have mentioned.

Generally, macroalgae and specifically Caulerpa raises pH overall, and especially when it is lit. I've measured the pH in and out of my refugia in the past and the effect was easy to see.

01/16/2010, 10:04 AM
Thank you, I'm going to keep an eye on it to see if it remains consistent.

Randy Holmes-Farley
01/16/2010, 10:24 AM

Let us know what you find. :)