pH dropping steadily tonight

[Shy_Koi]

Arggg - I hope someone is still up, I need some advice.....
Just got home from work and noticed that my tank's pH was 7.63 and dropping :eek:
It's usually still around 8.0 or so at this time of night. Morning low is around 7.8.
Checked the calibration of my pinpoint monitor and it's bang on. Also just ran some tests:
Salinity: 1.026
dKH: 9.5
Ca: 400
Mg: 1280
Temp: 79
No refugium
Water surface has good movement and there's a skimmer running.
I use Seachem's reef advantage calcium and reef builder to maintain Ca and alk.
Should I go ahead and drip in some pH buffer?
I've never used it before, but I'm afraid the tank may crash if the pH keeps dropping like it is....
If anyone has any advice, I'm all ears!
~Tamara

[IslandReefer]

Please check on the "look" of your corals before doing radical pH compensation. If they look "happy" don't do anything drastic...my vote is bum pH reading, assuming this is a sudden event.
Pinpoint meters are famous for wild readings and interference especially with the plug-in adapter...use the 9 volt battery see if that helps...I have one tank that when the PC lights are on I can't get a good pH to save my soul. :rolleyes:
Also how old is your probe they only have a apx 1.5 year halflife. :mrgreen:
If you can borrow another pH meter (or probe) ,do so and compare...not just the readings but the response also....mine tends to overshoot the high pH so it says 8.6 and up some times....unplug, recal (with fresh calibrators) and all is usually well. :cool:
Your dKH is high enough to buffer normal day/ night C02 effect to a change of less than 0.5 pH much more is harmful (so they say :smile: ).
How high does the pH get in midafternoon? (near the end of MH "day")
Good luck
PS if you are worried turn the lights back on tonightand see if the pH starts to normalize

[Nemo]

Just to add a bit to that you realy should run some buffer through the meter every once in a while to re calibrate


Robert

[Shy_Koi]

It was a looong night... :confused:
Thanks for the replies IslandReefer and Nemo!

Re: the pH monitor; the first thing that I did was check it with pH 7 and pH 10 solutions. It was exactly on - didn't have to make any adjustments. The probe is 6 months old and I always use a 9v battery - had heard that the adapter could give strange readings with interference.

The tank's daytime high is ~8.2 and I've had lows down to 7.7 in the early am. I generally try to keep dKH at 10.5, so it dropped a bit lower than usual yesterday. I find that I need to add SC Reef builder every 2 days to maintain that level. I do have plans to run a lighted refugium opposite to the tank's photoperiod, but (like everything else) it's still not completed...

The lights had been off for approx 3 hrs when I got home, and most everything was in sleep mode, so it was difficult to tell if anything was stressed. I did end up dripping in a dose of reef buffer (pH had dropped to 7.60 by that time). It slowly came up to 7.70 But this am it had dropped back down to 7.59
When the actinics come back on, I'll have a good look at the inhabitants :)
Thanks again for the help!
~Tamara

[Shy_Koi]

Just to add a bit to that you realy should run some buffer through the meter every once in a while to re calibrate

Robert

Hi Robert,
How do I run buffer through the meter? Soak the probe in buffer, or actually use a solution of it to calibrate?
Thanks,
~Tamara

[Nemo]

Just put your probe in a known solution and check the reading versus the solution. If it is out at all most have a calibration pot to adjust until you get the reading you are looking for.
Going from memory I test it at 4 and 9, but that kent buffer for the tank is 8.2 and that should be close enough for the upper end test.


Robert

[Aquattro]

I don't believe those readings. Corals can actually start dissolving below 7.7. I used to have tons of pH problems. Solved them all by throwing away my pH meter. Although it may be a cool gadget, I'm confused why we run them. They may be useful for tuning a Ca reactor, but monitoring pH full time? I now look at my fish and the coral polyps, they tell me how the water is doing.
I don't believe hobbyist meters can accurately measure pH full time for very long without a lot of tinkering and cleaning of probes. When I had my pH problems, I used 4 different calibrated meters, and got 4 different readings. Borrow a meter or buy a cheap test kit to verify the readings you're getting. If you have livestock in there, you should notice odd behaviour at 7.59....

[Shy_Koi]

If you have livestock in there, you should notice odd behaviour at 7.59....

You're right Brad, nothing seems affected this am. (fish, inverts, softies, lps & sps).
Guess I hit the panic button too soon :redface:
Thanks for the replies everyone.
~Tamara