New PH test kit, Way off from Liquid test

So I got an API PH test probe. Went throught the calibration and put it in the sump.

Back Story - So I always read my Red Sea PH test as 8.4 / 8.6 depending on the shade of purple I was seeing that day.

When I put in the probe it read 7.9. I added my seachem 8.3 and it went to 8.4. Now in the am it is 7.9 again. I know one reading is less than the otherr, AM / PM cant remember which.

So do I believe the API probe over the liquid kit ?

Cheers

 

I personally don't love liquid kits as they lose accuracy with age, and you don't know how long they've been on the shelf at the LFS. Also, look at the fish. If you raise it to work with the probe and the life in the tank don't like it then go with the liquid test kits. If they are happier with the probe's readings, go with the probe. I would trust the probe more. JMO.

 

Do you mean Aquarium Pharmaceuticals Inc? I thought they only make the liquid tests.

 

whats the brand of your probe?

 

No I'm sure that's a typo. I suspect they meant AMI (or American Marine Inc otherwise known as Pinpoint).

 

Sorry, yes it is the PinPoint PH tester

 

If you are only dropping to 7.9 overnight, I'm not sure I would have any concerns. Wait until mid-afternoon and then test again.

 

Cant you just leave the probe in there. Mine always stays in the tank. 7.9 is quite normal in the morning unless you have a robust fuge.

Probe will give you better reading than the liquid test. Those colors i could never get them to match the ones on the charts.

 

I am leaving it in the sump, but this is a new and my first probe.
So I am shocked at the difference between them.

I do know PH fluctuates, just wasnt expecting it to be so much lower than I thought it was.

 

Something to keep in mind with the Pinpoint monitor(PP).

Your ph will fluctuate between day and night as you said. So dont freak out. The PP will need to be calibrated every 6 months to work correctly. You will also need to clean the tip of the probe with a soft tooth brush every so often. My ph hits 8.16 at its peak and lowers to 8.0 at its lowest at night. These monitors are a double edged sword,if you ask me.
They will let you know where your at without busting out the manual test kits, but sometimes to much knowledge is dangerous. You will find yourself constantly checking the monitor. Luna