Monitor

[SPC]

I have been wondering about this for quite some time but have waited thinking I would read the answer some place, well if I did I didn't realize it.
My question is, why is there not a monitor made for calcium and alkalinity that works along the lines of a Pinpoint PH monitor? Be gentle with me, I'm sure its something simple that I haven't been able to grasp.

Steve

 

[SuperLeet]

Ive been wondering that too. Thats the main reason for not getting a octopus or other monitoring system

 

[BReefCase]

If you are looking for a probe that sits in the water and monitors continuously, I am not aware of any such thing for Calcium or Alkalinity, even in industry, except for huge specialized continuous reactor-stream analyzers costing millions.

However, if you really take your reef test kits seriously, are a reef-gadget guru bored with your Nilson Calcium Reactor, or are looking for that perfect gift for the techno-reefer who has everything, you might want to check out the web site of Orbeco-Hellige Analytical Systems at www.orbeco.com and look at their Analyst Model 975-MP.

This little gizmo is a multi-purpose automatic water analysis computer that performs most of the tests reefers commonly do on tank water.

The catch is you still have to put a captive water sample in a vial into the machine. But, for the cost of a mere 900 bucks plus reagent refills, you'll never again have to sit and stare at one of those annoying little color charts, or count chemical drops trying to decide if the sample has reached its endpoint yet.

Just read the digital display, dump the results to the printer, or save them on your personal computer.

What'll they think of next?

[ August 02, 2001: Message edited by: BReefCase ]

[ August 02, 2001: Message edited by: BReefCase ]

 

[SPC]

Up

 

[randy holmes-farley]

Alkalinity cannot be measured with a simple probe, since it is not a chemical but rather a measure of how much acid it takes to drive the pH down, and is influenced by a variety of ions in the water. One could design a system that withdrew a sample, titrated it with acid, and then discarded the sample, but that would be very, very expensive.

One can buy calcium selective electrodes that distinguish Ca++ over Mg++ and Na+ sufficiently for reef purposes (about 50x and 1000x, respectively), but they are expensive ($500+) and then you need an ISE meter as well (a few hundred to a thousand dollars).

 

[Nathan1]

Someone asked this question a month or so ago:
http://www.reefs.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=1&t=026480

Here are some pics of alkalinity probes, but like Randy says it's a "one shot" system, not continuous:

-Nathan

 

[SPC]

Thanks alot for the info guys.
Randy, do you think there is a possibility that a hobbiest type monitor could be developed in the future that would give the calcium data, or is this just not feasible.

 

[randy holmes-farley]

I don't really know. I'd guess it very unlikely for the price to drop to the level of Pinpoint monitors in the near future.