test kits
 

I've been wondering what test kits (brand) I should buy.

I've found an API master test kit for $15.00 (includes pH, high-range
pH, nitrite, nitrate, and ammonia). Since basically any two kits
allone would cost this much, I think its a good buy. But I was
wondering if people have suggestions other than the API kits. I've
tried dip strips but have real trouble reading them since they never
seem to stop changing color.

I would also like a KH and GH test (I have very hard water). I was
told that I shouldn't care about GH only KH and that the GH tests are
worthless since the testube can never be cleaned well enough to get a
good second reading. I was wondering what peoples comments are on
this.

In article , says...

I've been wondering what test kits (brand) I should buy.

I've found an API master test kit for $15.00 (includes pH, high-range
pH, nitrite, nitrate, and ammonia). Since basically any two kits
allone would cost this much, I think its a good buy. But I was
wondering if people have suggestions other than the API kits. I've
tried dip strips but have real trouble reading them since they never
seem to stop changing color.

I would also like a KH and GH test (I have very hard water). I was
told that I shouldn't care about GH only KH and that the GH tests are
worthless since the testube can never be cleaned well enough to get a
good second reading. I was wondering what peoples comments are on
this.


I've tried quite a few of them. Many are not worth the powder it would take to
blow them up. One of the general purpose ones that I find decent is the Tetra
Laborett. It comes in at $13-15 mail order and includes tests for pH, ammonia,
nitrite, GH and KH. It also includes a handy syringe for taking water samples.

For nitrate, I think the standalone Tetra is the one I find easiest to get a good
reading. But it has 4 reagents, one being zinc powder. The Hagen and some other
kits have finely divided zinc in solution in a bottle which can be problematic.
Also, Hagen's kit is an example of the kind that I find very hard to read. There
is no color change, only the saturation of the color changes. This makes it hard
to get a good reading, especially when comparing the liquid in a test tube to
printed paper.

All the GH and KH test kits that I have seen are easy to use and work well. Unless
you have some really unusual water conditions it is easy to repeat the test and
get the same result. These are all titration tests, so there is no color
interpretation. Just count the number of drops until the color changes
dramatically.

For nitrate, I think the standalone Tetra is the one I find easiest to get a good
reading. But it has 4 reagents, one being zinc powder.

For me, the Tetra kit you're speaking of seemed to just be more work.
There were so many things to keep track of. I was frequently worried
that I didn't measure properly or consistently from one test to the
next and I hated that the zinc powder was always visible no matter how
much I shook the thing. I ended up switching completely to API kits.
Also, Tetra has a 10 minute waiting time instead of 5 with API. I'm not
one to cut corners but I feel that API offers better peace-of-mind.

In article .com,
says...
For nitrate, I think the standalone Tetra is the one I find easiest to get a good
reading. But it has 4 reagents, one being zinc powder.

For me, the Tetra kit you're speaking of seemed to just be more work.
There were so many things to keep track of. I was frequently worried
that I didn't measure properly or consistently from one test to the
next and I hated that the zinc powder was always visible no matter how
much I shook the thing. I ended up switching completely to API kits.
Also, Tetra has a 10 minute waiting time instead of 5 with API. I'm not
one to cut corners but I feel that API offers better peace-of-mind.

I must agree, three liquids and a powder makes it one of the most complicated
tests. But I still think is produces good results for an inexpensive kit. Your
concern about measuring consistently may not be justified. A good chemistry assay
will use all or most of the reagents in excess, so the color change only depends
on the thing that you are detecting. The zinc powder in the Tetra kit would be an
example of that.

Every nitrate test kit that I have seen uses zinc powder. I had one kit from Red
Sea that contained the zinc in solution. I was using it to monitor nitrate levels
in a sal****er aquarium, where reef creatures can be much more sensitive to
nitrate than freshwater fish. The test kept coming up with only 2.5ppm nitrate, a
good result. I marveled at the efficiency of the live rock and sand bed in
removing nitrates. I began to suspect nitrates when there were some problems with
the tank, and tested with the Tetra kit. The Tetra reading was 25ppm. Upon
inspection I could see that the zinc powder in the Red Sea test was mostly stuck
to the bottom of the dropper bottle. So what I was measuring at 2.5ppm was not the
aquarium nitrate, but how much zinc powder was still free in the test kit.

In another case, I purchased an AP ammonia test. (Aquarium Pharmaceuticals, I
think different from API) The readings were absurdly low, showing nearly 0 ammonia
when I knew there should be easily measureable amounts. The Tetra test came
through as expected. The AP tablets were foil sealed and near, but not past the
expiration date. An email to AP went unanswered. Into the trash for that kit...

Between these experiences and what is commonly available here in the US, and
price, I ended up with these kits and most are Tetra. When the experts want to
boast about having confidence in their aquarium measurements they often refer to
Hach or Lamotte kits. Those are really expensive, like $30 or more for a single
test.

(I had assumed that API was Aquarium Pharm Inc., If that's not the case
then I meant Aquarium Pharmaceuticals when I was referring to the test
I now use.)

I've used 3 nitrate tests now.
First, those stupid little dip stick tests that constantly gave me
nitrate readings between 30 and 80 ppm. Then I tried the Tetra test we
were just speaking of, which made me realize my nitrate levels were
really much lower (around 8 -10 ppm) and I had been freakishly
performing water changes for no real pressing reason. After that box
was gone I switched to the Aquarium Pharm reagent bottle type for the
reasons I listed earlier and have been using it ever since. The results
were pretty consistent with Tetra.

The dip stick tests are completely useless. You might as well just pick
a number arbitrarily out of thin air.

George Pontis wrote:
In article .com,
says...

For nitrate, I think the standalone Tetra is the one I find easiest to get a good
reading. But it has 4 reagents, one being zinc powder.

For me, the Tetra kit you're speaking of seemed to just be more work.
There were so many things to keep track of. I was frequently worried
that I didn't measure properly or consistently from one test to the
next and I hated that the zinc powder was always visible no matter how
much I shook the thing. I ended up switching completely to API kits.
Also, Tetra has a 10 minute waiting time instead of 5 with API. I'm not
one to cut corners but I feel that API offers better peace-of-mind.


I must agree, three liquids and a powder makes it one of the most complicated
tests. But I still think is produces good results for an inexpensive kit. Your
concern about measuring consistently may not be justified. A good chemistry assay
will use all or most of the reagents in excess, so the color change only depends
on the thing that you are detecting. The zinc powder in the Tetra kit would be an
example of that.

Every nitrate test kit that I have seen uses zinc powder. I had one kit from Red
Sea that contained the zinc in solution. I was using it to monitor nitrate levels
in a sal****er aquarium, where reef creatures can be much more sensitive to
nitrate than freshwater fish. The test kept coming up with only 2.5ppm nitrate, a
good result. I marveled at the efficiency of the live rock and sand bed in
removing nitrates. I began to suspect nitrates when there were some problems with
the tank, and tested with the Tetra kit. The Tetra reading was 25ppm. Upon
inspection I could see that the zinc powder in the Red Sea test was mostly stuck
to the bottom of the dropper bottle. So what I was measuring at 2.5ppm was not the
aquarium nitrate, but how much zinc powder was still free in the test kit.

This brings up a question I have. I lost the little measuring scoop for
the powdered reagent that came with my Seachem nitrate test kit. Before
I lost the scoop, I always noticed that the scoop of powder didn't quite
dissolve (the solution was saturated). The kit came with a 10 ppm
standard so I tried testing without the measuring scoop by putting the
powder in to saturation. I got the expected colors for RO water, a tank
that's been stable around 2-3 ppm nitrate, and the 10 ppm nitrate
standard. I don't have enough standard solution to run every time. Am
I OK assuming that as long as the powdered reagent is slightly in excess
the kit will give a reasonable answer?

--
Elaine T __
http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com

In article , eetmail-
says...

This brings up a question I have. I lost the little measuring scoop for
the powdered reagent that came with my Seachem nitrate test kit. Before
I lost the scoop, I always noticed that the scoop of powder didn't quite
dissolve (the solution was saturated). The kit came with a 10 ppm
standard so I tried testing without the measuring scoop by putting the
powder in to saturation. I got the expected colors for RO water, a tank
that's been stable around 2-3 ppm nitrate, and the 10 ppm nitrate
standard. I don't have enough standard solution to run every time. Am
I OK assuming that as long as the powdered reagent is slightly in excess
the kit will give a reasonable answer?


In my experience the powdered metal is always in excess. Your Seachem test kit is
very likely using a similar assay. My bet is that it should work just fine so long
as you ensure sufficient reagent to reach saturation. Perhaps a lurking analytical
chemist can jump in at this point and say something more definitive.

Now that we are talking nitrate test kits, I looked again at the Hagen kit. It
uses a variation on the theme, cadmium instead of zinc. Kordon has two nitrate
tests that both use cadmium. (They also have an informative web site with detailed
product information for the technically inclined reader: http://www.novalek.com/)
I thought cadmium was on the list of things to avoid and am surprised to see
elemental cadmium in a consumer test kit. I suppose this is nothing to compare
with the amount of cadmium in a NiCd cell, but it makes me think twice about
running tests on the kitchen countertop. A while back I think I saw some kit that
used pyridine. Maybe time to shun the test kits and embrace Tom Barr's EI !