Stupid Question... Which one do I trust?

JeffDubya · 09-19-2007, 01:38 AM

So as the new prop tank project takes shape, a couple new pieces of equipment will make their way into my fish room. The first, today, an American Marine Pinpoint pH Monitor

So... Aquarium Pharmecuticals shows my water to be consistently 8.4 pH.

This new gizmo says no... 8.02.

Which do I believe?

And if the answer is what I think, then why in the hell are we paying money for a product that is *so* wrong? And we wonder why we get spikes. If I am dosing based on that information, it's bound to happen sooner or later.

V · 09-19-2007, 05:30 AM

reagents can become suceptable to the whole range of environmental conditions that can effect effectivness. age for one is a killer.
probes on the other hand , your a) relying on a factory setting, & b) relying on your own calibration method.

same time, same depth, i think not, however you should be able to find the factory variance of the prob, keep your reagents comfortable & find the happy medium between the 2 ..lol

regardless of which way you look at it, its only a guide. The swing isn't that much concidering the changes that occur natrally.

**CarmieJo** · 09-19-2007, 08:50 AM

Have you calibrated your monitor with solutions of known pH?

JeffDubya · 09-19-2007, 12:56 PM

Quote:

Originally Posted by CarmieJo

Have you calibrated your monitor with solutions of known pH?

Yup, bought the calibration kit and dialed it in before I used it. Should be accurate to within .01 pH

**Phurst** · 09-19-2007, 01:32 PM

I think I would trust the probe as well. There are so many variables in hobbyist grade test kits, there's bound to be some variability.

JeffDubya · 09-19-2007, 03:58 PM

Does anyone else here own this brand of meter?

**CarmieJo** · 09-19-2007, 07:58 PM

I don't have one but if your calibration solutions were reading correctly go with the meter. Just for kicks I'd probably use my kit on the calibration solution. Also, for a hobbyist grade kit being off by 5% isn't outrageous.

JeffDubya · 09-19-2007, 08:02 PM

Sorry... asking for a different reason... wondering how durable these are, could I use it between a couple tanks, or should I really mount and keep it in one...

**CarmieJo** · 09-20-2007, 12:51 AM

The lab grade ones are pretty durable. The probe has to stay wet.

JeffDubya · 09-20-2007, 01:40 AM

So just carry it upstairs in a glass of RO/DI water? Would that work?

**CarmieJo** · 09-20-2007, 02:09 AM

I think that would be fine.

Stargazer · 11-08-2007, 03:40 PM

I'd use tap or tank water. I do not know about PinPoint, but my Hanna instructions say not to put the probe in distilled or DI water.

Reefbaby · 11-09-2007, 03:30 PM

usually pH probes should be kept in a buffer solution, not in water

V · 11-10-2007, 03:56 AM

yeah, RB is correct. Probes are calibrated with step buffers & in between testing clean with water , RO/DI is ok for cleaning, however never to store it with this water, cuts the probe life. Also never wipe the end completely dry & store moist with 4M KCL inner solution or a ph4.0 buffer solution or gel.

Reefbaby · 11-10-2007, 06:11 AM

actually you should never even really touch the end of the probe...it's very fragile and sensitive.

V · 11-10-2007, 06:29 AM

were not all heavy handed lab ants such as yourself RB