Two nitrate test kits - huge difference in results
 

So I decided to get into this planted aquarium business with my 20g
tank with several Crypt wendtii and Anubias nana barely hanging on for
a couple of yeas now due to low light (half-dead 20W fluorescent),
lack of CO2 and fertilization (all other plants died off). I started
by adding a 55W power-compact from AHsupply and some fertilization
from Seachem, added some fast-growing plants, and have the
Eco-complete substrate and CO2 regulator on order. No need to mention
that immediately I got a huge algae bloom ... but that's not the
question I wanted to ask now.

I bought two nitrate test kits: one from Red Sea which was rated as a
"decent middle-end" kit, and - for comparison and a peace of mind -
another one from Aquarium Pharmaceuticals. Now, instead of peace of
mind, I have a headache. At the first measurement, the Red Sea test
gave ~8 ppm NO3 (between 5 and 10), while the AP test - 80 ppm! One
week later, the Red Sea shows 2.5 ppm, and the AP - 20 ppm, and
finally one week later - 0 ppm on the Red Sea test, and 5 ppm on the
AP. Tap water measures 0 ppm with both tests. So it seems that there
is a 10 times difference between readings (in the last measurement, 0
ppm on the Red Sea test could be as well 0.5 ppm). And yes, I followed
the instructions precisely and used the correct scale.

Now the obvious question is which test kit should I believe? The real
question, however, should be what is the reason of such a huge
discrepancy between test kits? Red Sea test kit uses 3 reagents, while
AP test kit - only 2 reagents, so they probably use different chemical
reactions. Could it be the interference from some other chemicals in
the water, such as phosphates (I have high phosphates at 1.5 ppm which
won't go down, in contrast to nitrates)? Anybody has any ideas?

Thank you,
OK

Two nitrate test kits - huge difference in results
 

"OK" wrote in message
om...
So I decided to get into this planted aquarium business with my 20g
tank with several Crypt wendtii and Anubias nana barely hanging on for
a couple of yeas now due to low light (half-dead 20W fluorescent),
lack of CO2 and fertilization (all other plants died off). I started
by adding a 55W power-compact from AHsupply and some fertilization
from Seachem, added some fast-growing plants, and have the
Eco-complete substrate and CO2 regulator on order. No need to mention
that immediately I got a huge algae bloom ... but that's not the
question I wanted to ask now.

I bought two nitrate test kits: one from Red Sea which was rated as a
"decent middle-end" kit, and - for comparison and a peace of mind -
another one from Aquarium Pharmaceuticals. Now, instead of peace of
mind, I have a headache. At the first measurement, the Red Sea test
gave ~8 ppm NO3 (between 5 and 10), while the AP test - 80 ppm! One
week later, the Red Sea shows 2.5 ppm, and the AP - 20 ppm, and
finally one week later - 0 ppm on the Red Sea test, and 5 ppm on the
AP. Tap water measures 0 ppm with both tests. So it seems that there
is a 10 times difference between readings (in the last measurement, 0
ppm on the Red Sea test could be as well 0.5 ppm). And yes, I followed
the instructions precisely and used the correct scale.

Now the obvious question is which test kit should I believe? The real
question, however, should be what is the reason of such a huge
discrepancy between test kits? Red Sea test kit uses 3 reagents, while
AP test kit - only 2 reagents, so they probably use different chemical
reactions. Could it be the interference from some other chemicals in
the water, such as phosphates (I have high phosphates at 1.5 ppm which
won't go down, in contrast to nitrates)? Anybody has any ideas?

For what it's worth, do a Google search on "red sea test kits" and "aquarium
pharmaceutical test kits" ... I think you'll find a lot of "they're
terrible" posts regarding Red Sea, and a lot of "they're OK" posts for
Aquarium Pharmaceuticals.

Two nitrate test kits - huge difference in results
 

|| So I decided to get into this planted aquarium business with my 20g
|| tank with several Crypt wendtii and Anubias nana barely hanging on
|| for a couple of yeas now due to low light (half-dead 20W
|| fluorescent), lack of CO2 and fertilization (all other plants died
|| off). I started by adding a 55W power-compact from AHsupply and some
|| fertilization from Seachem, added some fast-growing plants, and have
|| the Eco-complete substrate and CO2 regulator on order. No need to
|| mention that immediately I got a huge algae bloom ... but that's not
|| the question I wanted to ask now.

Welcome to the hobby... hahaha...

|| I bought two nitrate test kits: one from Red Sea which was rated as a
|| "decent middle-end" kit, and - for comparison and a peace of mind -
|| another one from Aquarium Pharmaceuticals. Now, instead of peace of
|| mind, I have a headache. At the first measurement, the Red Sea test
|| gave ~8 ppm NO3 (between 5 and 10), while the AP test - 80 ppm! One
|| week later, the Red Sea shows 2.5 ppm, and the AP - 20 ppm, and
|| finally one week later - 0 ppm on the Red Sea test, and 5 ppm on the
|| AP. Tap water measures 0 ppm with both tests. So it seems that there
|| is a 10 times difference between readings (in the last measurement, 0
|| ppm on the Red Sea test could be as well 0.5 ppm). And yes, I
|| followed the instructions precisely and used the correct scale.

This is pretty typical for most kits.. one may be older, and the regents do
expire... even if bought new, you won't know how long they've sat before
being sold...

|| Now the obvious question is which test kit should I believe? The real
|| question, however, should be what is the reason of such a huge
|| discrepancy between test kits? Red Sea test kit uses 3 reagents,
|| while AP test kit - only 2 reagents, so they probably use different
|| chemical reactions. Could it be the interference from some other
|| chemicals in the water, such as phosphates (I have high phosphates
|| at 1.5 ppm which won't go down, in contrast to nitrates)? Anybody
|| has any ideas?

Good luck on finding a good answer... I've managed to 'live' with my
results, because of the frustration of varying kits... Get one, a good one,
verify that it's 'close' and negotiate life as best you can...

--
RedForeman ©® future fabricator and creator of a ratbike
streetfighter!!! ==========================
2003 TRX450ES
1992 TRX-350 XX (For Sale)
'98 Tacoma Ext Cab 4X4 Lifted....
==========================
ø¤°`°¤ø,¸¸¸,ø¤°`°¤ø,¸¸¸,ø¤°`°¤ø,¸¸,ø¤°`°¤ø,¸¸¸,ø¤° `°¤ø,¸¸,ø¤°`°¤ø


is that better??

Two nitrate test kits - huge difference in results
 

On 10 Jun 2004 15:48:29 -0700, (OK) wrote:

So I decided to get into this planted aquarium business with my 20g
tank with several Crypt wendtii and Anubias nana barely hanging on for
a couple of yeas now due to low light (half-dead 20W fluorescent),
lack of CO2 and fertilization (all other plants died off). I started
by adding a 55W power-compact from AHsupply and some fertilization
from Seachem, added some fast-growing plants, and have the
Eco-complete substrate and CO2 regulator on order. No need to mention
that immediately I got a huge algae bloom ... but that's not the
question I wanted to ask now.

I bought two nitrate test kits: one from Red Sea which was rated as a
"decent middle-end" kit, and - for comparison and a peace of mind -
another one from Aquarium Pharmaceuticals. Now, instead of peace of
mind, I have a headache. At the first measurement, the Red Sea test
gave ~8 ppm NO3 (between 5 and 10), while the AP test - 80 ppm! One
week later, the Red Sea shows 2.5 ppm, and the AP - 20 ppm, and
finally one week later - 0 ppm on the Red Sea test, and 5 ppm on the
AP. Tap water measures 0 ppm with both tests. So it seems that there
is a 10 times difference between readings (in the last measurement, 0
ppm on the Red Sea test could be as well 0.5 ppm). And yes, I followed
the instructions precisely and used the correct scale.

Now the obvious question is which test kit should I believe? The real
question, however, should be what is the reason of such a huge
discrepancy between test kits? Red Sea test kit uses 3 reagents, while
AP test kit - only 2 reagents, so they probably use different chemical
reactions. Could it be the interference from some other chemicals in
the water, such as phosphates (I have high phosphates at 1.5 ppm which
won't go down, in contrast to nitrates)? Anybody has any ideas?

Thank you,
OK


I don't trust test kits because they don't agree, I don't trust my
skill in making changes to bring test results to some desired level
and I am not convinced the changes are worth the trouble.

I do have kits in my supplies. I have not thrown them away and when I
am not sure if I have a problem I have used them. I figure the
numbers may not be accurate, but they can indicate a shift from the
last time I used them. Netmax says kits age, so I am not sure I can
even trust the kits for comparative uses.

I watch my fish and plants for color and behavior changes. Regular
weekly water changes mean my tap water is the standard I use. I will
be in trouble if the community water content changes, but I trust it
more than I trust myself. I can't even remember to take all of my own
pills. g

dick