Help! Really high PH, cant get it to go down.

[Thekegk]

Help! I have a 135gal tank that I am having a issue with high PH all the sudden. backstory, I was doing normal dosing on sunday I used seachem 2 part to raise my alk 7.8 and calcium 400 a little. in my tank its roughly 20ML to raise alk about .5. Monday I went to check my seneye while at work and noticed it wasn't online since Saturday PH8.4, I got it connected late that night, it took a reading and I realized my PH was at 8.88 :-0! it was already too late, store was closed, no way to lower PH. no biggie if I over dosed the ph will slowly drop back to normal. Tuesday I monitored seneye and PH was still 8.72-8.84, after work I tried soda water with very little change, so I switched to vinegar. I slowly brought the PH back down to 8.4 over about 5 hours. Wednesday I woke up to PH back at 8.74 raising to 8.82 again during the day. I got home my tank was cloudy and looks like calcium is starting to precipitate. what the heck!!!!!. so I did about 20 gal water change to hopefully lower the PH but I am still at 8.74 currently. I don't know what to do. I am thinking of trying to do 50% water change but I don't know why the PH is still out of control.
my tank. I have tested the PH with test kit but not since sunday. I don't think seneye is issue as the cloudy water shows calcium precipitate(unless its a big bacterial bloom?). I will test PH with drop kit later today
135gal Display
30gal sump
reef oct skimmer
3 radion xr30
carbon
Doseing pump isn't setup yet and anything else I dose by hand but haven't since sunday. no kids, no one but me touches the tank. wife wants nothing to do with it but look at it when it is pretty.

what do I do?

 

[chipmunkofdoom2]

Have you ever calibrated the Seneye's pH sensor? Is that even possible? A pH reading of 8.82 seems unlikely, especially at an alkalinity of 7.8 dKh.

What I'm guessing is that the vinegar you dosed caused a bacterial bloom, which is the cloudy water you're noticing. The vinegar likely caused a temporary drop in pH because it is a weak acid (acetic acid). Then bacteria begin to grow, feeding on the vinegar, resulting in the milky white water you noticed. As the acetic acid is consumed by the bacteria, the pH naturally will go back up because the acid is being removed from the water column.

Try to get another method of testing pH and confirm your results. A pH of 8.7 - 8.8, especially without dosing calcium hydroxide, sounds a lot like testing error.

 

[Thekegk]

Hi Chipmunk, thanks for the quick response! there is no calibration I know of. the seneye uses a slide. it is coming to end of life in about 8 days(30day slide, would really stink if it has issue at the end with monitoring). I will test my PH with my API kit tonight when I get home to verify. if I did setoff a bacterial bloom with the vinegar should I do a water change or just ride it out? as far as PH nothing is upset, all my frags are still showing polyps, bubble tip is a little mad but only after the cloud happen. fish all seem normal as well. I did skip a feeding yesterday since the water was so bad.
Forgot
8.2 alk as of tues. will test again tonight
0 - ammonia
0 - nitrite
0-5 nitrate API color test looks like 0
haven't tested phosphate.

 

[Savage338]

First post here on this site. Had same issue with my seneye. How old is your slide? Only getting 20-25 days out of mine. Using on a 300 gal. FOWLR. No dosing. New set-up only running for 2 1/2 months. Ph goes from 8.1 to 8.5 overnight. Replaced slide back down to 8.1. Happened last 2months

 

[Thekegk]

so I just remoted home to pc and was looking at seneye and found a setting that somehow was in-checked "is this a marine aquarium" I checked it and bam PH at 8.44" yup wont be using seneye for PH monitoring any more. I guess there was a software issue Saturday and when it disconnected it reset all my settings.

this is why we always need to do testing with different methods and not rely on only one. lesson learned. still learning even after 4 years in hobby.

thread can be closed now.

 

[Callok]

It sounds like the probe is off. If you can't calibrate, you can always test it against a known value. You can probably pickup some calibration fluid at your LFS, chemical supply house, or hydroponic store. You can use it to test your probe's accuracy.

I keep a portable pH meter handy, since I don't always trust my Apex probe. If it shows a large change, step 1 is always re-calibrate the probe and check against the pH meter before I even think of doing something to the tank.

 

[Randy Holmes-Farley]

FWIW, pH is NEVER too high without adding high pH additives such as limewater or using new artificial rock..

 

[BluewaterLa]

I agree with others that testing errors should always be thought of and the last thing you ever want to do is freak out and immediately start to make any changes or a bunch of changes for that matter IF the corals and fish still are happy and healthy.

No matter how long a person is in this hobby mistakes will happen and we all will have bone headed moments.
Reefing is like a roller coaster, UPs and Downs

 

[Hans-Werner]

I agree that it is impossible to have permanent high pH without adding something like limewater. With lots of light the corals can raise the pH to maybe 8.5 or 8.6. High pH increases the oversaturation with calcium carbonate and at some point calcium carbonate would start to precipitate on pumps and heaters which would release CO2 and in this way limit the pH increase.

 

[kennedpa]

I agree that it is impossible to have permanent high pH without adding something like limewater. With lots of light the corals can raise the pH to maybe 8.5 or 8.6. High pH increases the oversaturation with calcium carbonate and at some point calcium carbonate would start to precipitate on pumps and heaters which would release CO2 and in this way limit the pH increase.

Agreed. I was running 8.2s to 8.4s and now with things growing well I'm seeing 8.3s to highest 8.56 so far. I've never heard anything that's is naturally past 8.5 before.

 

[Deniss]

Did you soak the slide for 48 hours before putting it in your seneye ?
Did you touch the "solution paths" on the slide with your fingers?
Make sure your seneye gets good flow.
These things can make incorrect readings of your PH