phuzzykins
New member
I went ahead and ordered a Martini low-range phosphate photometer. Another toy to add to the fish room. 
Thanks for all of the replies!
Thanks for all of the replies!
Most human-readable phosphate test kit?
- Thread starter phuzzykins
- Start date
Billybeau1
Premium Member
Good luck. Keep us posted on how you like it.
Tom, you can't right click the mouse over a misspelled word ? Or are you just being funny ?
Tom, you can't right click the mouse over a misspelled word ? Or are you just being funny ?
Tom, you can't right click the mouse over a misspelled word ? Or are you just being funny ?
Must be browser specific? I miss the spell checker too.
Must be browser specific? I miss the spell checker too.
HighlandReefer
Team RC
ieSpell - A Free Spell Checker for Internet Explorer. Works great for me.
http://www.iespell.com/download.php
http://www.iespell.com/download.php
phuzzykins
New member
I haven't had much of a chance to evaluate it yet, but I have some initial impressions.
Firstly, the build quality is not fantastic. Mine is missing a rubber foot on the bottom, has a couple of scuffs on the top, and the o-ring that seals the battery compartment doesn't fit all that well. One of the cuvets requires more torque than I really feel comfortable with to seat the lid firmly enough for it to fit into the meter.
Secondly, those little foil reagent packs leave a lot to be desired. There's either a little or a lot of reagent adhered to the inside of the packet by static, depending on how much you persuade it to leave. I'd prefer a liquid reagent and a syringe, or a bulk powdered reagent and a measuring spoon.
Thirdly, the reagent takes forever to dissolve. So long that on my first attempt, the meter had shut itself off before the reagent had completely dissolved. When powered back up, the meter doesn't remember the previous zero point, so that sample became useless.
Both my 300 gallon reef (brand new) and my 34 gallon tank (overgrown with hair algae) read 0.01 ppm. I'd like to get some phosphate reference solutions to test before I believe those numbers. They could be accurate, but I expected them to be higher.
Cheers,
-Matt
PowermanKW
New member
So I finally got my D-D Merck test kit. It is pretty easy to use. Directions were not that great, but yo ucan figure it out.
But ya, for such a high sensitivity test, it was pretty hard to read. The good news is I am way low. Definitely on the end of the scale.
So the last three colors are form 0-.3. Well my best guess was .015. Which is good. My problem was that while I could sort of tell the tint, it was lighter than the blank sample. So with it being lighter, it was just hard to tell. I'm going to try tomorrow in some day light. Might be better.
Also... it said the sample needed to have a PH of 3-9. to add acid of base as needed. Well mine is 8, but that is a pretty wide range. Does it matter if I'm close to one end? Does it effect the result?
But ya, for such a high sensitivity test, it was pretty hard to read. The good news is I am way low. Definitely on the end of the scale.
So the last three colors are form 0-.3. Well my best guess was .015. Which is good. My problem was that while I could sort of tell the tint, it was lighter than the blank sample. So with it being lighter, it was just hard to tell. I'm going to try tomorrow in some day light. Might be better.
Also... it said the sample needed to have a PH of 3-9. to add acid of base as needed. Well mine is 8, but that is a pretty wide range. Does it matter if I'm close to one end? Does it effect the result?
Should be fine.
Does it read in phosphate ion, or phosphate-P? Some kits are the latter, and the numbers look low and the sensitivity looks artificially high due just to the units used.
Does it read in phosphate ion, or phosphate-P? Some kits are the latter, and the numbers look low and the sensitivity looks artificially high due just to the units used.
Billybeau1
Premium Member
Well, I use Mozilla Firefox, so maybe that is what I am seeing with the spell checker.
Never did like Internet Explorer.
Never did like Internet Explorer.
tntneon
SPSahollic
@Randy :
-At work i can use an lab icp to determine P concentrations .
But we first have to run an blanco sample to make the baseline ,normaly we test minerals dissolved in osmotic water and then the blanco is ultra pure water.
If we want to make a good PO4 - salt water measurment do we have to run a ultra pure or an salt water blanco ?
we already did the test with a blanco of ultra pure water , then the readings was 0.01 P , meaning 0.03 PO 4 if i`m correct.
greetingzz tntneon
-At work i can use an lab icp to determine P concentrations .
But we first have to run an blanco sample to make the baseline ,normaly we test minerals dissolved in osmotic water and then the blanco is ultra pure water.
If we want to make a good PO4 - salt water measurment do we have to run a ultra pure or an salt water blanco ?
we already did the test with a blanco of ultra pure water , then the readings was 0.01 P , meaning 0.03 PO 4 if i`m correct.
greetingzz tntneon
ScooterTDI
New member
I think you might run into problems trying to analyze saltwater on an ICP. The sample matrix is pretty concentrated and I think you'll get all kinds of interferences. You could dilute the sample at the expense of the LOD.
I think the problem with making a saltwater blank is that the salt mixture might contain some phosphate. Then you would only be measuring the phosphate concentration relative to that of fresh saltwater. If the phosphate content of your used water isn't much more than your fresh saltwater, you'll get an artifically low result.
Probably the best approach would be to run a series of phosphate spikes to diluted samples.
Scott
I think the problem with making a saltwater blank is that the salt mixture might contain some phosphate. Then you would only be measuring the phosphate concentration relative to that of fresh saltwater. If the phosphate content of your used water isn't much more than your fresh saltwater, you'll get an artifically low result.
Probably the best approach would be to run a series of phosphate spikes to diluted samples.
Scott
-At work i can use an lab icp to determine P concentrations .
What type? ICP-MS or ICP-AES?
A seawater blank is a good idea, IMO, but I doubt it could make the value get any higher, only lower.
What type? ICP-MS or ICP-AES?
A seawater blank is a good idea, IMO, but I doubt it could make the value get any higher, only lower.
duplicate post
PowermanKW
New member
Ya,, actually it says it only reads ortho phosphates but, the scale say mg/P ans mg/l PO4/3. What does that mean?
mg/P ans mg/l PO4/3.
If that middle word is "and" then it reads both and if you want to compare to most other kits, use the PO4 scale, which should give higher numbers.
If that middle word is "and" then it reads both and if you want to compare to most other kits, use the PO4 scale, which should give higher numbers.
tntneon
SPSahollic
-At work i can use an lab icp to determine P concentrations .
What type? ICP-MS or ICP-AES?
A seawater blank is a good idea, IMO, but I doubt it could make the value get any higher, only lower.
thx Randy
,It`s an ICP -AES i think (i`m not the responsible lab technician in my team , i go over procescontrol and production
).But we had a simular discussion in my team whether we should use seawater or ultra pure blank for measuring PO4 in seawater (part of the team that loves my hobby
).We will look in the very big manual of the device or ask the lab manager if he knows to make sure.
greetingzz tntneon
If it is an ICP-AES, I'd ask them to show you the peak for phosphorus to see that it looks normal and isn't just integrated noise or interference from other ions. I did that here for various tests, as in Figures 1 and 2 for cadmium:
Purity of Calcium Chloride
http://www.advancedaquarist.com/issues/mar2004/chem.htm
Purity of Calcium Chloride
http://www.advancedaquarist.com/issues/mar2004/chem.htm
PowermanKW
New member
mg/P ans mg/l PO4/3.
If that middle word is "and" then it reads both and if you want to compare to most other kits, use the PO4 scale, which should give higher numbers.
Sorry Randy, I don't get it. So then when I saw the number .02 is what we should be under for reef tanks.....02 what?
And yes it does give higher numbers, and I didn't get that. I thought that was just higher in the scale. See... their directions are not that clear... well at least to me.
