15 years of experience and I'm stumped

[mhaith]

For the last three days my PH meter reads 7.3 at lights on. It has never read less than 7.8, even in winter with windows closed. Within an hour of lights on, it recovers to the typical PH cycle eventually reaching 8.3.

I have checked calibration, ALK, Calc and all params are fine. I dose BRS 2 part via LM 3. All coral 'canaries' and fish are acting normally.

About a week ago my large Derasa had a spawning event which my two skimmers handled without issue in my 210g mixed reef with sump. Yesterday my skimmers went crazy, were back to normal by this morning but the PH still read 7.3.

I have attached an old pic for reference. Suffice it to say the clam is another 50% larger so it was a good sized 'event'.

The closest I can figure is a bacteria bloom? But then why such a strong daily PH recovery?

 

[milesofreefs]

do you fun a refuge?

 

[milesofreefs]

run**

 

[mhaith]

Huh?

 

[milesofreefs]

i meant run. if you have a refuge try running your light cycle at night or 24h lighting on it it tends to keep the ph level in check during the night.

 

[mhaith]

Thanks, good advice for those looking to start a tank and create a more stable PH cycle.

However, please reread my initial post. I am searching for the cause of an atypical tank event.

 

[Stanley-Reefer]

Ca reator? Is the probe in there bad?

 

[mhaith]

Ca reator? Is the probe in there bad?

Nope. In the original post I say I use BRS 2 part

 

[disc1]

Have you tried recalibrating? The probe may be going bad on you. If the slope has changed then the meter could be reading it as a larger change than what is actually happening.

 

[Ron Reefman]

In the original post:

I have checked calibration, ALK, Calc and all params are fine.

 

[snorvich]

Have you tried recalibrating? The probe may be going bad on you. If the slope has changed then the meter could be reading it as a larger change than what is actually happening.

That would be where I would look first. I absolutely do not trust pH probes as they degrade and become unreliable. But if all corals and fish are acting normally, I would get a new probe, calibrate and go onwards.

 

[mhaith]

I will try a new probe. Maybe the slope is the factor as the PH 'recovers' quite quickly (within an hour) with lights on. This one makes the most sense.

What threw me was the skimmers a few days ago. I'm sure I was searching for corroborating events.

Monitor showed normal (7.8) this morning after a week. I'll see if it continues.

 

[snorvich]

What threw me was the skimmers a few days ago. I'm sure I was searching for corroborating events.

Skimmers handle spawning events well. Back when I monitored pH I replaced probes about once every 14 months.

 

[mhaith]

Skimmers handle spawning events well. Back when I monitored pH I replaced probes about once every 14 months.

Agreed, I use my PH monitor as an indicator of ALK fluctuations.

 

[jcw]

I just discovered the same thing. pH was 7.5 or less first thing in the AM.

Do you use tank covers? I'm considering removing the glass tops on my tank.

I also started running my kalk just at night.

Strange phenomenon.

The pH will come up to normal in the afternoon like yours so even if it's a slightly off pH probe, either the AM is too low or the PM is too high.

I wouldn't worry about it other than I've heard that at a pH of 7.3 coral skeletons start losing the calcium carbonate.

 

[jcw]

I have attached an old pic for reference. Suffice it to say the clam is another 50% larger so it was a good sized 'event'.

Holy cow! that clam looks huge in your old pic. 50% bigger now?

 

[Joboo]

Holy cow! that clam looks huge in your old pic. 50% bigger now?

Have you tested PH with a test kit?

 

[mhaith]

That is a simple and elegant question and believe it or not did not even occur to me. Everything is back to normal now so either the probe self corrected or some factor, that remains to be explained, caused the week long event.

 

[TampaSnooker]

perhaps the proteins and amino acids from the spawning broke down. a surge in ammonia will acidify the water as the gamates break down.

 

[mhaith]

perhaps the proteins and amino acids from the spawning broke down. a surge in ammonia will acidify the water as the gamates break down.

It is a possibility but the acidity would not simply be present at night.