Hanna Phosphorus Checker Inconsistent

[blackflme]

So I've been having inconsistent results with the Hanna Phosphorus checker. I've been searching and searching and I see this is a very common problem. I've been trying to take notes on what everyone says to help improve consistency. It's not working for me and it's so frustrating! What am I missing?

I just completed 2 back to back tests with the same cuvette. First test came back at 63ppb and the second test came back with 133ppb. I used a turkey baster to put water into a small cup. Both test were used from the water in the cup. I strained the water through filter floss to reduce particles. Even after doing this there were small amounts of particles floating in the glass. Is this an issue and how can I fix it?

1. Put gloves on
2. Srain water through filter floss into small cup.
3. Use turkey baster to fill cuvette with exactly 10ml of water
4. Cut open reagent on two sides to form a funnel to get ALL of the reagent into the cuvette.
5. Wipe cuvette with paper towel so there are no smudges.
6. Place in hanna checker with 10ml label facing me and hit the button.
7. Remove cuvette and set time. Place reagent in cuvette and invert for 2 minutes.
8. Wipe cuvette of any smudges
9. Place into checker with 10ml facing towards me and hold button until 3 minute timer comes on.

 

[RCS82]

Is this the ULR checker?
I would assume so from the ppb you mentioned. Mine is never the most consistent but that's fine. I use it to basically to tell me if my PO4 is either low, medium or high, that's all.

 

[Velcro]

Why are you doing all those extra steps (collecting from a glass instead of directly from the aquarium, putting through filter floss, etc)? Really adding way too many variables right there... who even knows if there might be some phosphorous on that filter floss by chance.

The other thing is that you should ideally NOT be wiping the cuvette again after the "tare" on the device unless you are 100% certain that they had the same amount of smudges in the same places. What I mean is that if there was a slight smudge left on the first "tare" reading, and then you wipe it again before the actual test you could mess it up by change what it saw at the tare.

 

[Velcro]

Also, no offense but I lol'd when I read gloves.

 

[SPR1968]

So I've been having inconsistent results with the Hanna Phosphorus checker. I've been searching and searching and I see this is a very common problem. I've been trying to take notes on what everyone says to help improve consistency. It's not working for me and it's so frustrating! What am I missing?

I just completed 2 back to back tests with the same cuvette. First test came back at 63ppb and the second test came back with 133ppb. I used a turkey baster to put water into a small cup. Both test were used from the water in the cup. I strained the water through filter floss to reduce particles. Even after doing this there were small amounts of particles floating in the glass. Is this an issue and how can I fix it?

1. Put gloves on
2. Srain water through filter floss into small cup.
3. Use turkey baster to fill cuvette with exactly 10ml of water
4. Cut open reagent on two sides to form a funnel to get ALL of the reagent into the cuvette.
5. Wipe cuvette with paper towel so there are no smudges.
6. Place in hanna checker with 10ml label facing me and hit the button.
7. Remove cuvette and set time. Place reagent in cuvette and invert for 2 minutes.
8. Wipe cuvette of any smudges
9. Place into checker with 10ml facing towards me and hold button until 3 minute timer comes on.

Firstly welcome @blackflme

So my points of advice:

I don’t strain the water through filter floss, no need for that.

I don’t bother with gloves but that’s me.

I hold the cuvette with my handkerchief all the time and take particular care not to spill the white powder on my handkerchief (for obvious reasons in particular drug control when I wipe my nose afterwards! lol)

When you have placed reagent in the cuvette you need to shake it for 90 seconds or as long as you dare before the bloody Hanna checker shuts off! Practice makes perfect here.

Joking aside, if you keep the test file spotless in a handkerchief or similar that should avoid many of the problems.

 

[lapin]

Welcome
To test your meter you need a std.
https://www.bulkreefsupply.com/hi736-11-phosphorus-standards.html
This will tell you where your meter is as far as being calibrated. If this test comes out the same each time you will know it is your method that is flawed and not the meter.

 

[blackflme]

So i didnt start with all of these steps. But i was getting readings that varied from .07ppm to .6ppm. Thats way out of range and makes the test useless. So i started adding steps based on videos and what other people do to see if its something im doing. I wipe the glass multiple times to insure its clean and there are no spots added since doing the "tare" and mixing the reagent.

The filter floss is brand new. I didnt do that before but i read particles could throw it off so i gave it a shot my tests started with tsking the water out of the aquarium right into the cuvette, no gloves, etc. That just didnt work. I wasnt going to come here asking questions when the videos ive seen say to use gloves etc.

Ive just come to a point where ive tried everything. When i convert the readings i posted it goes from 0.193ppm to 0.408ppm and thats hardly accurate by any means.

Btw, i put a small amount of water through the floss and into the cup. That same small amount of water was used for both tests. That way the water would have no variance. If there was anything on the floss it would should affect both test equally. Even if the results were off they should be the same.

 

[dwest]

So i didnt start with all of these steps. But i was getting readings that varied from .07ppm to .6ppm. Thats way out of range and makes the test useless. So i started adding steps based on videos and what other people do to see if its something im doing. I wipe the glass multiple times to insure its clean and there are no spots added since doing the "tare" and mixing the reagent.

The filter floss is brand new. I didnt do that before but i read particles could throw it off so i gave it a shot my tests started with tsking the water out of the aquarium right into the cuvette, no gloves, etc. That just didnt work. I wasnt going to come here asking questions when the videos ive seen say to use gloves etc.

Ive just come to a point where ive tried everything. When i convert the readings i posted it goes from 0.193ppm to 0.408ppm and thats hardly accurate by any means.

Btw, i put a small amount of water through the floss and into the cup. That same small amount of water was used for both tests. That way the water would have no variance. If there was anything on the floss it would should affect both test equally. Even if the results were off they should be the same.

bummer...Exactly which kit are you using? Rcs82 asked that earlier and I think it might matter. My ulr kit gives me all the precision I need. Yours is not....

 

[blackflme]

I use the phosphorus ulr that reads in ppb ranging from 0-200ppm.

 

[goober]

 

[Mako61]

I use the ULR and it does vary some, but not enough make a difference. I do basically your steps 3+.

the main things I try to do:
rinse vial once and get exactly 10ml ( tank water only )
keep the vial clean / smudge free
face vial same way
dont get bubbles - ie dont shake
care to get all of the powder into the vial

 

[blackflme]

Goober, thanks for posting. But as you can see my readings are way outside of the error range. 63ppb(0.193ppm) and 133ppb(0.408ppm).

Mako, how much does yours vary?

I just want a way to make sure my GFO is working and when to change it. One day i tested and it said 24ppb and then the next day it read 200ppb(which is maxed out). I just want to be able to trust it.

 

[Scorpius]

I found that using a stopwatch allows me to use the almost 3 minutes to shake the vial and I have also found shaking the vial pretty forcefully the first 30 secs really minimizes the microbubbles.

 

[blackflme]

I just did two more back to back test. Both read at 37ppb. Thats a first lol.

 

[blackflme]

I found that using a stopwatch allows me to use the almost 3 minutes to shake the vial and I have also found shaking the vial pretty forcefully the first 30 secs really minimizes the microbubbles.

I also use a stopwatch. I shake it for 2 minutes almost exactly.

 

[dwest]

I just did two more back to back test. Both read at 37ppb. Thats a first lol.

Even though you had precise results today, if I were you, I would contact the manufacturer.

 

[Mako61]

Goober, thanks for posting. But as you can see my readings are way outside of the error range. 63ppb(0.193ppm) and 133ppb(0.408ppm).

Mako, how much does yours vary?

I just want a way to make sure my GFO is working and when to change it. One day i tested and it said 24ppb and then the next day it read 200ppb(which is maxed out). I just want to be able to trust it.

Here are the reading I have done. I started my tank April 2017. I do question the one reading I got that was 0.39 I think I upped my GFO too much in April and bottomed out my phosphate. I mix GFO into my GAC I only have 1 reactor. I vary the amount some based on Hanna readings.

 

[Scorpius]

I also use a stopwatch. I shake it for 2 minutes almost exactly.

You have 3 minutes from when it says C2 after you zero it out.

 

[blackflme]

I probably should contact hanna. Originally i thought it was something i was doing, but it seems that achieving decent results is much easier than i thought.

Thanks for sharing your results mako.

 

[MrPike]

I run a maintenance company and we use those testers quite a bit. Basically, they suck, but are one of the only options. I second the suggestion to use them as a "Low" "Medium" "High" indicator instead of worrying about the numbers exactly. Also, careful of microbubbles when you shake the vials, they tend to throw stuff off. You don't need to jackhammer it to get it to mix, just casually twist the vial up/down. Keep the vials clean, rinse with freshwater after use, store dry, and follow Hanna's advice on opening the satchels, as lots of the product can get stuck in the corners.

Dreadful product really, but gives a ballpark.