Another pH/Alk Thread

mneville277

New member
So I have read all of the threads here, all of the linked articles - to the point my brain hurts, but I am no closer to a solution.

My pH will not come up and has been low for two weeks now. Now I know the common rule is don't worry about pH if alkalinity and calcium are good, but my pH will not come up above 7.72 (measured with API and verified with calibrated probes) and dips to 7.4 prior to the lights coming on. Alk is 12 dKH, calcium at 480ppm and have been for the same time period with no significant fluctuation.

I have not dosed since the numbers started creeping up, and have done 20% water changes every 48 hours in the hopes that it would correct itself, as the most prevalent advise goes. Alkalinity and calcium have not moved at all. Dropped an air stone in a sample to see if it comes up from excess CO2, but no change. Opened the window directly next to it in case the house has excess CO2 - solid at 7.72.

6 month old 20g long tank, SG - 1.023, ammonia, nitrites, and nitrates all at 0, 78 degrees, 50x turnover with lots of surface agitation, no changes to the tank recently other than the addition of an RKL and using IO Reef salt. Tank houses softies and LPS, one birdsnest, one 6-line wrasse and a handful of dwarf ceriths. All livestock are doing really well with the exception of my leather which closed up as the numbers went wonky and hasn't opened since, but other corals are showing visible growth from day to day, no visible signs of stress from the wrasse. I do run carbon and dual Current USA Orbits (got a deal...).

So do I leave it provided alk and calcium remain high or is there a way to fix it? Don't want to chemically chase pH and invite those issues. Can anyone give a non-scientific, non- formula-heavy, explain it to me like I'm 5 kind of answer?
 
[welcome]

I am skeptical about a measurement of 7.4. The live rock should be dissolving at some point. Alkalinity at as 12 dKH should be okay, although I might get a second opinion on the test kit, just in case.

Water changes won't help with pH problems. Assuming the alkalinity and pH numbers are reasonably accurate, the air around the tank is high in carbon dioxide. Opening a window and getting fresher air often helps, although the weather doesn't always cooperate. Does the tank have a skimmer? Sometimes, poor aeration can be an issue. Does the water surface have a good strong rippling to break up any surface film? That can make a difference, too.
 
Thanks for the welcome - been lurking and researching for a while as I got things set up.

I'll grab a different brand test set tomorrow to make sure on the dKH - the calcium falls within range of being balanced, so I didn't question it before. I calibrated the pH probe 3 times today just to make sure I was getting an accurate reading and ran the API test to verify. I don't run a skimmer, but the surface agitation is nice and strong and I have never had the protein slick. I have a Koralia on one side pointed at the front glass and slightly towards the water surface that keeps it relatively choppy to augment the WP10.

Anyone run a vent fan from the window to the tank before? Might be a project - an aesthetically pleasing system to bring outside air into the tank to diffuse the output of CO2...
 
Probes can be inaccurate due to electrical interference, for example, and no amount of calibration will change that.

People have tried a number of schemes to reduce the carbon dioxide level. Running a vent from the outside might help. Another idea is a carbon dioxide scrubber.
 
So I grabbed a new test kit and two different brands of strips for giggles - my pH came up to 7.81 at its highest point (verified by all sources), 11 dKH, and 440 calcium - both down from previous. Nitrites came up to <.50 ppm, but still 0 ammonia and nitrates.

Best part, the leather finally opened back up today. So whatever went haywire seems to be correcting itself (knock on wood). I won't start dosing again until things are stable for a few days and see if the pH continues to rise.

Just found it odd that in everything I read, this situation was not addressed. I would love to know what caused this all of a sudden when the numbers have always been so stable.

I appreciate your input!
 
Okay, well, 7.81 is okay, although I'd worry about the daily low as well.

This parameter spike probably is going to go undiagnosed. I'll try to think some more about what might be happening, but my best guess is that the carbon dioxide level in the house spiked for some reason. Gas heating or gas utilities can do that, as can the arrival of a lot of guests.
 
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