Ph meter am i missing some thing?

[Joe,

I have one and do NOT like it at all. Sometimes I can get it to calibrate and sometimes it acts erraticly. I just bought a new one that I LOVE, but it was also approx. $75. There is a reason it is $20. It could be that I just got one that is annoying. I'd say save your money for a better one.]
 
[Joe,

I have to agree and disagree with Jody; yes they do seem a little erratic. Since I have one, and at this point cannot afford to replace it with the more expensive model, I have done some research and found out a few things.

I read to make sure you suspend the probe in your sample. If you place it in a container and the probe is resting on the bottom, you will get a different reading than if it is suspended. This supposedly has to do with the probe being sensitive to pressure and resting on the bottom affects the way it reads. I also read that they are supposed to be able to adjust to different temperatures. This is the reason they act erratic when you put them into the solution, they have to adjust.

When ever I use mine to either calibrate it or take a reading, I place the sample in a small container. This can either be an old yogurt container for water samples (I have never been able to get an accurate reading directly from the tank with moving water) or an old camera film container for calibration solutions. I drill a hole just smaller then the size of the probe in the lid so if fits snug. I rinse the probe in some RO water and then I shake it like you would an old fashion mercury thermometer. Don’t know why, just something I read in a post, at the very least it helps dry it out from the rinsing. Then I put the probe in so it is in the solution but not touching the sides or bottom, I swirl it around for a few seconds, again, do not know why just another suggestion from a post but probably helps make sure any rinse water is substituted with the test solution, and leave it for at least 10 minutes. During this time it will swing both high and low, but after a while, it stabilizes and only fluctuates by .01. This is what I use as my reading. Just to check it sometimes I will swirl the solution again, wait a few more minutes and again it will stabilize at the same reading. I also keep mine in a small container of storage fluid when it is not in use. YOU MUST keep the probe wet at all times. If it dries out it is ruined. I got all of my stuff from a place called Pulse Instruments. They do not charge shipping. I cannot remember what I paid for mine but I do not think it was $40, I guess the price has gone up a little. Here is a link to the site.

Pulse Instruments

None of this has come from the manufacture, just from research on different boards and messages from other reefers who use this meter. Following the above suggestions has really helped. I have compared the results against a SeaTest pH test kit and they look to be the same. With all that said, as with just about everything in the hobby, you get what you pay for, and I think this is one item for which that statement holds true.]



Edited By SALT on 1081183555
 
[Being that I am having a battle with low Ph (7.8 - 8.0), I needed to make sure that I know my reading is fairly accurate so I don't do anything stupid. So, I decided to go with a more expensive model. The one I just received is very easy to calibrate (no adjusting the screw, just a button push), has ATC (automatic temperature compensation) and displays the temperature, will tell me when I need to recalibrate, will tell me when the probe needs to be changed, will store up to 15 readings, and you can detach the pH probe and put on an ORP probe and it automatically detects which probe it is. Mine is a portable meter, so it is not one that you keep in the sump constantly taking measurements, but it doesn't sound like you are looking for that type since you are looking at the Hanna. I definitely feel more confident and comfortable in the readings I get with this one than the Hanna, but maybe it's because I didn't have all those idiosyncrecies worked out like SALT.]
 
[Excellent choice of words Jody :D

It sounds like the one you ended up with is awesome. What brand/model is it?

Joe,

My posting was not intended to be a sales pitch for these things, more of a heads up. Jumping through all of those hoops just to get a reading that I feel is accurate is allot more involved then I really care for. I look forward to the day I can purchase one more like Jody's. On the other hand, I feel it is better than a sharp stick to the eye, oops I mean using the test kits and determining the color variations. If you can really get one for as cheap as some of those still out on the auction it might be worth the $10 - $15. Not much more then a good test kit. Don't forget it needs calibration fluids and storage fluids also, so that will add to the price. In the end it is a judgment call. It will not do you any good if you do not have confidence in the results is gives you.]



Edited By SALT on 1081193848
 
[Salt,

Mine is made by ExTech is called an ExStix pH meter (model PH100). They have a newer model that you can refill the probe fluid (model PH110). It's the same except for the ability to refill probe fluid and it's more expensive. I also forgot to mention, you can not only buy an ORP probe to use on the unit, but you can also get a Chlorine probe. Here's a description page:

ExTech ExStix

Let me know if you have more questions about it. I really like it myself. I just got it Friday and have used it twice, so time will tell as to whether it lasts in the long run.

PH100.jpg
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Edited By buyitjody on 1081195864
 
[HI
Thanks for all your input, I was just hoping for once not to have to spend a fortune on some tester.. I have always had trouble reading the test kits. So I guess I will just have to save up and get a good one.
Joe]
 
[Hydro,

Each time I've seen a pH Monitor come up for sale here on our board, I bought it. :D They sell used for $50, and more for new.

Matter of fact, I think we had a group buy for them recently, where they were $69 new, which is about $20 off the normal going price. I love knowing the pH of the tank any time of day or night, and leave it in the sump turned on all the time.

This is one of those purchases that is worth it - you'll have zero regrets.]
 
[Joe,

Please figure out what you want first. Ask yourself the following questions:

1. Do I have space (or want one) in my sump/under the cabinet to have one that constantly takes measurements? (If yes, then get the one like Marc has. Many folks like it -- Pinpoint pH monitor. If no because you don't care to have constant readings or don't have any room for one in cabinet or sump (like me), then make sure you find a portable one like mine.)

2. Do I want a throw-away one or one that I can replace the probe on? Be aware that not all pH meters have the ability to replace the probe. The Pinpoint (one Marc uses) and mine do have the ability to replace the probe. The probe will last usually 1 - 1.5 years. My probe costs $29 to replace. Unless you get an insanely expensive meter, the probe will usually cost between $20-$45 to replace depending on the unit. Some pH meters are made to just toss after the probe goes bad. Just be aware of what you are getting and what the price will be to replace the probe. You might not want to get a particular unit with a replaceable probe if the probe repacement is going to cost more than what you want to spend when the time comes. In that case, look at other meters whose replacement probes will be less expensive. If you don't want to deal with replacing a probe (which is not hard, usually just screws off), then get a meter that is disposable in the end.

Hope this helps even more in making a good decision on your pH meter purchase.]
 
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