I hate test kits!

fishytime · #1 06-19-2009, 04:12 PM

A couple of weeks ago I finished off my Elos DKH test kit. My DKH had been low (according to the Elos kit) so I had been slowly trying to get and keep it up near 9. The only replacement kit we had at the shop was an API so i brought that home and was getting the same lowish reading as the Elos kit. We finally got some Salifert kits in so I grabbed one of those and it tests out at 12.5

WTF?....Test with the Sali kit again....12.2

...test with the API kit....9....So which kit do I believe?

Delphinus · #2 06-19-2009, 04:38 PM

Welcome to my world dude. If you want to really have fun go spend $200-300 on some electronic monitor and still get conflicting results. Testing is ***awesome***.

The Codfather · #3 06-19-2009, 04:44 PM

Do what i do. NOTHING.

christyf5 · #4 06-19-2009, 05:08 PM

Split the difference, 9-12 is a good number anyways

Lance · #5 06-19-2009, 05:22 PM

Test Kits SUCK!!!!!!!!!!!!!!

Delphinus · #6 06-19-2009, 05:32 PM

Don't know a thing about this API test kit but with the Elos test kits, I've noticed they sometimes do these "corrections" to the instructions, like if one drop is intended to be equal to 100 of something, they might put a sticker over the card (not the detailed instructions) that say it's 75. Probably just coincidence here but 75 is 3/4 of 100 and 9 is 3/4 of 12 ..

I myself am through with Elos test kits. I never really understood the mass appeal of them to begin with, but between having been thrown off by confusing results and those glass test tubes that break just by putting the supplied stopper thing on them (I've broken at least 6 of those tubes just putting that plug on, or taking it off) I now feel totally burned by them.

The test kits I hated the least were Seachem. They come with reference solutions so you can "test your test kit" and can thus have some degree of confidence in your results. But nobody seems to carry them anymore. Oh, if only someone who worked at a LFS could take sympathy on the plight of the test kit abusee's and could look into ordering something better....

pterfloth · #7 06-19-2009, 09:27 PM

If you really want accurate alkalinity results then you can do what we do in the water treatment industry, use methyl purple indicator and N/50 sulfuric acid to titrate. The N/50 sulfuric acid is very dilute and harmless. Using a 50 ml sample of tank water, add 4-6 drops of methyl purple indicator and add N/50 acid until the color changes from green to purple. Every ml of acid added is 20 ppm of alkalinity, so 6.5 ml = 130 ppm alkalinity (dKH 7.3). A 4 litre container of N/50 sulfuric acid is about $82.00 from Fisher Scientific. That's good for over 600 tests!

I also use an industrial test method for calcium and magnesium. It's 100% accurate and much cheaper in the long run.

The commercial test kits are not very good and very over-priced. Like the commercial liquid calcium and magnesium additives, the mark-up is scandalous.

mark · #8 06-19-2009, 10:00 PM

The one before my last Salifert test kit came with a Alk check solution. Maybe put up a post looking for some.

btw, both my kits check at 7.0dKH with it.

Hairytank · #9 06-20-2009, 01:42 AM

I have the API test kit for dKH and Ca and have found them consistently low lately...6-ish and 380-ish. However, when I dose up to a dKH of 9 and Ca of 420 according to the API test the colours are way better in the acropora so I suspect the tests may be correct....I am soooo confused-ish...

fishytime · #10 06-20-2009, 03:15 PM

Ok so I tested again this morning....

API 8.5
Salifert 12.5

tested the check solution which is labeled 7.3....

and got 11.5 *wonders if salifert tests the check solution with their test kits*

so if I subtract 4 from my 12.5 reading I get 8.5 which is what the API test reads

The second salifert test kit from the shop was off the charts...according to that one my dkh is over 16.

I hate test kits!