Help - dosed the wrong thing!!

I leave it on and in the water 24/7. The reading should remain constant and only change based on actions effecting pH (photosynthesis, etc.). I ran a reef tank with a Ca reactor many years ago and had the same Pinpoint monitor and was able to maintain constast levels.

 

This is completely incorrect, CO2 causes your pH to go down from carbonic acid which promotes a reductive environment.

This is a really good article, Dingo I think you've got a bit confused, maybe read it again. Quote from Randy Holmes article: 'Clearly, the pH is lower at any given alkalinity when the carbon dioxide is raised. It is this excess carbon dioxide that leads to most low pH problems for reef aquarists.'
'Consequently, if an aquarium (or the air it is being equilibrated with) has "excess CO[SIZE=-1]2[/SIZE]" in it, that means that it has excess H[SIZE=-1]2[/SIZE]CO[SIZE=-1]3[/SIZE]. This excess H[SIZE=-1]2[/SIZE]CO[SIZE=-1]3[/SIZE], in turn, means the pH will fall'

Vinegar is a weak acid and you would need to add a lot of it to a reef tank to reduce a high pH. This is because a marine tank has a high amount of bicarbonate which buffers your pH. I wouldn't recommend adding vinegar because it is a carbon source and will cause bacterial blooms which can remove oxygen from your water and can easily suffocate live stock and will also promote cyanobacteria. Vinegar or any other carbon source should be added slowly and monitored when reducing nutrients in a reef tank but never used to reduce the pH.

 

Oh $hit - I hope i didn't do more damage than good! The pH did drop dramatically using just a tablespoon of vinegar but over night it crept back up. What else could be contributiing to the high pH or do you think its possible I have a bad probe?

 

Yes, I would say it's a bad idea to compare your liquid test (or pinpoint) tests to a test strip. Test strips are slightly worse than I am at guessing my tank params. Worthless they are, IMO.

My mistake Mac, for some reason I thought I read you were using a pH pen probe vs a "regular" probe. Nevermind what I said as it doesn't apply to you.

 

In general reef tanks are well buffered and if you get a protein skimmer, have your tank in a ventillated area and aim to keep your water parameters similar to NSW you shouldn't have a problem with pH. pH tends to fluctuate throughout the day and night so a spot check is never that accurate. Once you get your pH, alkalinity, magnesium and calcium in check using a decent salt mix you can start measuring more vital measurements.You need to then monitor ammonia, nitrite, and nitrate. Then just occasionally check pH (using a liquid test is as good as any for this). Until your coralline, any corals or other calcium/magnesium utilising organisma are established these should be kept in check with small fortnightly water changes.

I think the only thing which would have caused the high pH in your tank was the bicarbonate you added. Considering you have added a table spoon of vinegar, I would do a 30-40% water change with a good salt mix and RO water. The bacteria usually has a delay of 2 days, so you probably won't see anything yet, this buys you some time to get 2 30-40% water changes in.
If your tank goes cloudy don't panic, this will be the bacteria. I'd recommend getting a skimmer; this will remove the bacteria, their biproducts and oxygenate your system.

 

Which salt brand are you using?
Aim for
KH 6.5 – 9
Ca 400 – 420 mg
Mg 1250 – 1300 mg

Your pH at these parameters should be around 8.1-8.3.

 

Thanks all for your tips/suggestions. Here is the follow up.

Get home Tuesday night and the pH probe is reading 8.9. I'm like WTF?? but the percs and the softy frags I picked up recently (shrooms, polyps, GSP, xenia) all look fine. Okay, I decide not to panic and disregard the pH meter for the time being and just do a 10% water change. Done. I had an old Red Sea pH test kit - one step up from test strips - so I tested the tank with that and from what i could tell it was between 8.3/8.4. Those things suck as well because the readings never seem to fall into a definite category. I remove the probe from the tank and inspect it. Physically it seems okay. There is fluid inside the probe but I think it is suposed to be there. It's somewhat viscous so I'm assuming it isn't SW that has leaked in there. As a test I decide to submerge the probe in the 4.0 calibrating solution overnight to see what happens since I was having trouble keeping a steady reading. Next morning the it was holding steady right around 4.0 so that's good. I do the same thing with the 7.0 solution Wednesday night and yesterday morning the reading was holding steady near 7.0. Hmmm - seems to be working okay. I put the probe back in the tank and get a reading of 8.7-8.8. F#%K! I had a batch of SW mixing for my next WC so I decide to test that water and see what happens. Before doing so I tested the RO from my LFS and get a reading of I think 7.0. I could be wrong because I forgot the actual number but I do know it was a nice even number like 5 or 9 or 7 or something like that. It definitely wasn't 8 or 3 . What should RO test at?

Okay, I put the probe in the new SW mix and I get a reading of 8.8-8.9??? How is this possible? The SG of the SW is 1.026 and the temp was 80 degrees. I used the last bit of my Instant Ocean mix for this batch of water and it wasn't the IO Reef Crystals.

Am I nuts for thinking my probe may be bad even though it tested and held steady at 4.0 and 7.0 using the calibration solutions? Could the IO salt mix create that high a pH with RO water? I'm at a loss.

 

It sounds like faulty calibration solutions or probe to me. Your new salt mix when made up to 1.026 should be 8.1-8.3. If your Red Sea pH test kit reads 8.3-8.4 I would be more inclined to go with that although a second opinion from a friend or LFS with one of there test kits would confirm it.

 

3rd Update:

Went to the LFS this weekend to get their opinion and they were baffled as well?? They tested my probe in their main tank and got the same very high reading. They then asked if my probe had been calibrated and I explained to them the procees I had gone through this past week. They then determined the probe must be bad and should be replaced (which they were very willing to sell me one). I was in the process of forking over the cash for a new probe when one of the very young store associates who was now helping me starting asking other questions trying to determine what could have gone wrong. To make a long story short, this very sharp young associate picked up on the fact that I incorrectly used 4.0 and 7.0 solution for the calibration. he said I should be using 7.0 and 10.0 solutions. Instead of a probe he sold a small packet of 10.0 solution and voila...problem solved!!! After recalibration all readings now normal (RO water, newly mixed SW, and water in my tank).

This might be good info to post somewhere on the forum for future readers.

Thanks again to all for you advice adn suggestions!