pinpoint CA meter

[Funkyskunk]

I know there is a thread active at reef central, but have you guys had any experience with this yet, seems like it could be great thing to have, but not sure how stable and reliable it is.

Any comments ?

[Aquatic Image]

I am not really sure as to how good they are but I will let you know when mine comes in. I am told it should be shipping next week.

[Funkyskunk]

ok great would be nice to know,, thx

[gqjeff]

there is a GB going on for these in the equipment forum here...

[Aquatic Image]

Just got my CA monitor today. But I can not get it calibrated. Just shows error. Anyone else have this problem?

[nyfireman3097]

RC the guy had this problem if i remember correct he said he re read the directions and it was plain as day HTH
Nick

[Aquatic Image]

Thanks Nick. I will try to dig it up. Boy I have not been over to the other side in a while :crap:

[nyfireman3097]

lol yeah ill check it out for ya
Nick

[nyfireman3097]

ok ,after a couple of days of getting up and down results ,mostly up .i was nearly at my end .So rather than give up easy i started completly over except this time i soaked the probe for 6hrs in room temp tapwater.then i read the instructions again ,come too find i looked over the step of letting the calibration #s flash for 5 straight times in a row .Then I got a tupperware container and cut the top off with its lid still on ,then i flipped it upside down and ziptied it to my second chamber on my cal reactor away from the effullent return ,but i could have put it almost anywhere since my sump is very large (100 gal),i dont think there is a calm spot in any sump due to there design ,so this i thought would work well ,but to make sure i also put the probe inside a little glass vival ,then inside my tupperware cup in the sump ...Im happy to report my cal reading has stayed at 436 for over 24 straight hrs ,it has went to 446 for brief periods but back down to 436 ,my cal reading using a salifert test kit is 440 .I also have some comments to make on the probe fluid ,when i calibrate i leave the vent open ,then when im done calibrating i close the sleve other wise it will evaprorate in 1 day even less .This way it almost doesnt evaprorate at all ,and the reading are the same ...
SO FAR IM HAPPY

this is from RC HTH
Nick

[nyfireman3097]

when you put the probe in the 100 and 1000 solution it will take awhile till the # willl start to flash once it does wait till it flashes 5 straight continious time in a row then press enter (this is in the instructions)
good luck

[nyfireman3097]

I'd contact Lou. That sounds like maybe you pushed the wrong buttons or the meter is defective. Any time such a meter reads zero suggests a problem to me.

FWIW, I finished my testing and submitted my article.

Here's my conclusion:

Conclusions

My conclusion based on limited testing of two Pinpoint Calcium monitors, and from the information that I have received from several other aquarists who have them, is that they can be a useful way to measure calcium, but are not without issues that aquarists must become familiar with. Given the time to calibrate and equilibrate them to each new solution, such a monitor is not faster than a test kit. Since I have not tested the accuracy of any calcium test kits, I cannot compare the accuracy of the calcium monitor to typical commercial kits.

I was pleasantly surprised by the fact that the response does not seem likely to be thrown off by the ranges of different water chemistries encountered in reef aquaria. Temperature seems to be the only big concern, and that is something that aquarists can control.

The monitor is warranteed for 2 years, and it is recommended to replace the electrode after 18-24 months, or when it can no longer be calibrated. Pinpoint has replaced monitors for some folks that had problems (unable to calibrate). All of the measurements that I took were using the 9 volt battery, although one of the meters did come with an AC adapter.

The section below gives some tips for using the Pinpoint calcium selective electrode in reef aquaria. Pinpoint includes many other recommendations in their User’s Guide, which is well written and easy to follow. I have only listed those things here which are not listed there, or which I consider most important:

1. The calcium monitor will probably not give reliable readings for any solution other than seawater. I would not use it for fresh water, limewater (kalkwasser), or calcium supplement solutions (at least not using the Pinpoint seawater standards). It may or may not work properly in the low pH/high alkalinity solutions found in the effluent of a calcium carbonate/carbon dioxide reactor.

2. Temperature is critically important. Make sure that the calibration temperature and the measurement temperature are the same to within 1-2 ºF.

3. The electrode takes a while to equilibrate to the new solution. The longer it is left in, the more reliable will be the reading (within reason, very long times of a day or more may start to encounter some drift). The directions say to equilibrate during calibration until the meter gives 4-5 flashes of the concentration without stopping, but I would suggest leaving it in until it flashes steady without stopping. In taking measurements, I would leave it in for at least 10 minutes and watch the reading to see that it is not changing.

4. Do not tough the tip directly. It can be easily damaged.

5. The directions say to rinse the probe in fresh water between measurements or calibrations. If you are measuring a large volume, like a reef system, that isn’t important. If you are measuring in a small container (like a cup), it is more important to not transfer water between samples. Bear in mind, however, that some fresh water clinging to the probe will alter a measurement more than will the 100 ppm standard if you are going to read seawater. My suggestion is to gently shake the electrode between solutions to remove big drops, and possibly wipe the sides gently with a paper towel if you are taking careful measurements.

6. Turn off the meter between uses. It remembers the previous calibration, so there is no need to run down the battery.

Disclosure: American Marine/Pinpoint supplied the two calcium meters that I tested at no cost.


__________________

[nyfireman3097]

this is from reef central from the chemistry guy
Nick