PINPOINT pH Monitor + Calibration Fluids

Finally an accurate PH tester. the calibration method on this is a little bit of work compared to an auto calibrated unit, but THATS WHAT MAKES IT WORK so well. just stick it in the 7.0 liquid and 10.0 liquid back to back to back to back until it reads right by adjust the screw. little tip, you need a tiny flathead, a regular flathead wont work. dont be put off by the calibration its really simple. just takes like 5-10 min then your good to go with the most accurate reader thats actually reliable. and you can just permanently leave it in your tank too! you do need a 9volt battery

I've tried the $10 meters and the $50 meters and they were all crap. Even the $50 ones are inaccurate and don't calibrate well. This meter keeps its accuracy for about a month, and even then it's only off maybe +/-.1. Easy to calibrate. I dropped the whole unit in water, dried it out, and it still works perfect. Don't waste your money on cheaper ones, this is the one you want.

Great product and deal! Fast shipping! Thanks

running 24/7 in salt water tank only have to check the calibration monthy and is always with in 0.05 which is good for what I need to check. Calibration takes some time, that's way I only gave it 4 starts

Advantages: Fairly quick: reading stabilises in 30 seconds or less. Holds its calibration pretty well ( I store the probe in 3M KCl). [I'm only using it on solutions with pH between 7 and 10 so I can't comment on its use outside this range.] Disadvantages: There is no 'automatic' calibration, manual calibration is slow, and the two calibration screws work in opposite directions (the pH 7 screw turns clockwise to increase pH reading, the pH 10.01 screw turns anti-clockwise to increase pH reading) which can cause wasted time if you forget. The cable which connects the probe to the measurement unit is unscreened so if you are not careful it is significantly affected by the static from your body - you can see the reading change as you move closer or further away. So you must ensure the cable is completely uncoiled to prevent any induction effects. Update: I originally rated this 4 stars but the more I used it the more I liked it. I just ordered my third one! Now that I'm familiar with the manual calibration it goes fairly quickly and you can end up with a much more accurate result than the 'automatic' ones. The accuracy and repeatability are very good for the price.

I carefully followed the calibration instructions for this machine using the provided calibration liquid, and I quickly realized how sensitive the wires are to any touch! Just the slightest movement can affect the readings. After nearly an hour of focused effort, I finally got it to show 7.0 in the 7.0 liquid and 10.0 in the 10.0 liquid. What a relief to see that it was calibrated! However, when I placed the probe in my tank, I felt a little uncertain about the reading. To get a better understanding, I decided to verify its accuracy with my Redsea test kit. To my surprise, the probe's reading was significantly off. I thought maybe my Redsea kit could be the culprit, especially after all the time I had invested in calibrating this machine, so I tried a different test kit too. Both my pH test kit and the Redsea test kit confirmed the same results, while the probe continued to give an inaccurate reading. Although it's disappointing, I feel it's best to return this machine and explore better options!

Do not buy a ph pen or a ph controller or anything ph measurement related JUST BUY THIS and a 9volt battery and you're good to go I hope to god they make these forever because they are the absolute solid gold standard for this kind of thing in freshwater high energy planted tanks. I have three of these on separate tanks because I won't start a new tank setup without one. I will add not to purchase an AC adapter for these, I know that sounds cheaper and more permanent/efficient but if you do some research first, these are designed to be used with batteries because of the sensitivity of the probe. The current from a wired power adapter will interfere with the readings, all the time, badly. If you're interested, that is not a reflection on the product or manufacturer, that is literally just the science behind how ph probes and monitoring equipment work. This is the only thing I trust to keep a variety of really rare fish and plant sp alive, i'm talking setups that run well into and past the thousands of dollars. Long live the american marine pinpoint ph meter