Pinpoint PH monitors

[quarryshark]

Anyone had trouble with these? I have had mine since Jan. I just changed the battery on it a week ago and my PH (according to the monitor) dropped form 8.2 down to 7.8.
I recalibrated in a couple if times and the readings still run 7.9-8.0
Now I don't trust it. My PH could not have dropped that much in 10 minutes!!
I even took it to my LFS and compared it to his . His showed 8.3 and mine showed 8.0. He then pointed out to me that his had not been calibrated in months.
Should I replace the probe?

 

[darb2]

What does the manual test tell you? If a couple of sources tell you the meter is faulty, I would contact the manufacturer. I would hope they last longer than 8 mos

 

[darb2]

double post

 

[quarryshark]

I don't have a manual test, thats a good Idea, will get one tomorrow.
Accurate water testing IMO is the biggest pain with this hobby.
Thanks darb2....good thinking

 

[captivereefs]

Make sure you clean the probe tip. They tend to develop a clear slime on them that will cause a low PH reading. A tooth brush works good!

 

[jamal-188]

When my battery was low I got readings that were not correct either. I would wait to replace the probe until you can no longer calibrate it or it doesn't seem to hold true readings for any extended period of time.

 

[quarryshark]

Well the battery was replaced, it was calibrated several times, I scrubbed the probe with a toothbrush and I got a reading of 7.78 this AM. It was the same in my qt tanks. Either I have a serious PH problem or the probe is bad.
I'll go get a new probe today and take some water to my LFS, I need to find out.
Thanks all.

 

[quarryshark]

Well, new probe, same reading. Guess I will have to buffer.

 

[Fishboy-from-NY]

It's highly unlikely that the probe is malfuntioning since when I use to change the batteries before I pruchased the AC Adapter, I use to happen to me, what I use to do is keep it on for at least a day and it adjusted itself. If you want to make sure for comfort reasons, I would test the PH and then wait a day or two, if that doesn't work then yes your probe may be defective. Do you have your probe located inside your tank where fish can pick on it or in your sump. The reason why I ask is since the time I had the probe in my tank and my triggers and tangs were picking on it, the probe had to constantly be replaced and caliberated. After it was placed in my sump, I only caliberated it once every three month's, replace the probe every 1 1/2 Year and test the PH with a differenct test kit monthly to compare results.

 

[captivereefs]

When the probe is bad it will jump around and give an unstable reading not loose accuracy.

 

[pecan2phat]

Are you calibrating with known values of 4 & 7 or 7 & 10? You need to do this several times until the probe reads the solution accurately without the need of adjustment. As the probe ages, it will take longer to adjust or calibrate while in the solution and eventually, you will not be able to adjust or calibrate the probe any longer. HTH

 

[quarryshark]

Yes, good point. I have calibrated with both combinations several times. I did get a new probe yesterday and got the same readings. For some reason my PH evidently was taking a dive. Stated buffering yesterday. Now I just need to find out why its doing that.
Thanks all for your help.

 

[pecan2phat]

Also check your Ca & Alk. when these are out of whack, it can effect your PH. I once had high Ca & low Alk & this caused my PH to drop to 7.8 @ night & only got up to 8.0 during the lighting phase.
If your using a Ca reactor, this can also cause your PH to drop if everything is not configured right. (excess Co2)

 

[quarryshark]

Well, I checked the alk today and it is running 5.0meg/L. Of course I just buffered 48 hours ago, but I'll take it. My PH has also been steady at 8.2. I also did a 15 gallon water chenge yesterday. Water changes have been infrequent, I have had to concetrate of the qt tanks.
Hopefully we are OK now. Any thoughts??

 

[Sparky]

I had the same problem just 3 days ago. The day before I had a reading of 8.18 and all of the sudden I was down to 7.78.....I freaked! I re-calibrated 2 times and it never got better. Mine has replacable sensor heads, but it is fairly new and I didn't think that it could be bad that fsat, plus it will tell me when the head has to be replaced. So I did a quick water change thinking that it might raise the pH a bit, but no go. I took a sample to the LFS and he got a slightly higher reading than I did, but not too much.

I bought some "Reef Buffer" from Seachem and put it in there, and 15 minutes later I had a pH of 8.25.....and it is holding steady. It worked for me, you may want to try it out.

HTH

Mike

 

[quarryshark]

I used the same product with the same result. Go figure, maybe its something in the water (pun intended).
Thanks Sparky, lets keep in touch with this. I thought I was doing everything right and then this. Let me know if it holds, mine has so far.
Kurt

 

[Sparky]

Since my last post on the 7th, mine has been holding pretty good at around 8.198

I don't understand why it happened, but it hasn't happened again. How is yours holding up QS?

Mike

 

[quarryshark]

Yes, its been holding fine. I guess it just needs a boost from time to time...go figure. Scared the heck out of me though.
Glad everything is good on your end.