[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Phosphate Test Kit
- To: Aquatic-Plants at actwin_com
- Subject: Re: Phosphate Test Kit
- From: Greg Morin <greg at seachem_com>
- Date: Tue, 8 Jan 2002 10:38:52 -0500
- In-Reply-To: <200201062048.g06Km2w27413 at actwin_com>
- References: <200201062048.g06Km2w27413 at actwin_com>
>
>I've been using a Seachem Phosphate Test Kit for about a year now. Before I
>started dosing KH2PO4, the phosphate level was so low (~ 0.1 mg/l) that I
>didn't think much about it. But now, on Tom Barr's advice, I'm trying to
>keep the level at 0.5 mg/l. And, lately, I've begun to doubt the results of
>the test. This morning, I tested the reference solution that comes with the
>kit and, instead of getting the 1.0 mg/l I should have, I got about half
>that.
>
>So, my questions are: Do the reagents "expire" in as little as a year, or is
>this test kit inherently inaccurate? If the latter, does anyone have an
>opinion on which of the more expensive Hach or Lamotte kits would be better?
>Thanks.
With the phosphate kit it is very, very , very important that exactly
one full stem of sample be used. A little bit more or less will throw
off the color. Also, take the reading between 10-30 seconds as the
color does shift off scale the longer it sits. If the cap on
phosphate reagent#1 has not been on or has been kept loose then the
reagent can evaporate slightly and this will also alter the test
result (normally not a problem but I mention it because very old
phosphate kits won't work because of this i.e. 5+ years).
--
Gregory Morin, Ph.D. ~~~~~~~Research Director~~~~~~~~~~~~~~
Seachem Laboratories, Inc. www.seachem.com 888-SEACHEM
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~