Calcium Test Kits

[wrassie86]

Randy
I was wondering if you knew of any side by side tests that had been done on any of the calcium test kits. normaly i use salifert calcium but the kids got ahold of it for there own testing.and my new one wont be here for a few days.i dont need to test my calcium very often,not as much as Alk but after worring about it i desided to test with my other test kits and here are the readings done twice.

Aquarium Pharmaceuticals Ca 2 + test kit == 460ppm

Seatest kit ==340ppm

My alk is 3 meg (salifert)but that is a big difference in readings.I have been told that the AP test is close to sailfert but seems to easy as its only 2 liquids..Any thoughts

[Randy Holmes-Farley]

I do not recall seeing a careful comparison of different calcium test kits under realistic aquarium conditions. I vaguely recall seeing some tests that a club ran, but IIRC, it wasn't using a standardized seawater.

Anyone recall that test?

I've not used the two kits that you have there, so I can't comment much on them. Anyone have opinions on them?

[wrassie86]

Randy
Thanks, guesse when my new salifert gets here i will put these other 2 kits up against it and maybe buy a few more kits localy and see if any are close. What kit do you use?

[Randy Holmes-Farley]

I've used Hach and Salifert. I'm in the process of testing a calcium probe on some carefully measured standards, and may test my Salifert kit at the same time. :)

[wrassie86]

Originally posted by Randy Holmes-Farley
I've used Hach and Salifert. I'm in the process of testing a calcium probe on some carefully measured standards, and may test my Salifert kit at the same time. :)

Will you post those results?i'd be more than happy to send you the different test kits i have and then a few, as im sure others would also.
if not is there any easy way i could make a regent to test with?i know Sechem comes with one but theres no way of knowing if its right on either. i would just like to know the ones that are close verses the ones that are a complete waste of money.like one of the ones i have if not both :rolleyes:

[Randy Holmes-Farley]

I'll be writing an article on the meter. I'll probably mention the test kit result here or possibly in the article (although testing the kit is not the point of the article).

Testing it is complicated and will take me quite a while to get an appropriate seawater type standard. Seachem supplies a standard with their kit, but I cannot vouch for it.

[wrassie86]

thats what thought, guesse i will do alittle testing on my own.
I like the thought of the calcium meter.but to me a alk meter would be the greatest thing to come along.but i know that will probly never happen.

[Randy Holmes-Farley]

No, I think you'll be waiting a while on an alkalinity meter. But maybe someday a bicarbonate meter, which would accomplish the same thing. :)

Good luck with the testing.

[Mariner]

Randy,
I'm sure this has been discussed before, but do you think we can/should draw any conclusions about the accuracy of certain test kit brands from table 5 in this article (http://www.reefkeeping.com/issues/2002-04/rs/feature/) by Dr. Ron? His suggestion seems to be to that we can only trust hobby kits as a "rough measurement".
Mariner

[wrassie86]

So occording to that article it looks like the seachem was better than the salifert? Did i read that right?\

Mariner
thanks for the read.

[Randy Holmes-Farley]

I wouldn't draw any interpretation from that table. The water samples were measured in different ways, measuring different types of calcium (ICP measures solid CaCO3 particulates, while the kits may not), and at different times (the samples may have changed between tests) by lots of different people that may or may not have been using their kits properly. It is also assumed that the ICP was perfectly accurate, and it may not be.

[wrassie86]

Well heres what i got in my own little test.all done at the same time.

Sailifert kit 3 tests about 450

A/P test kit-3 tests about 420

seatest kit-2 tests about 315

[Randy Holmes-Farley]

Thanks, Rob. :)