HANNA ULR PHOSPHATE checker being weird? Anyone?

[BanjoBandito]

My ULR checker is all over the map....I just ran a phosphate test and the first round said ".82".....I ran it again and it's now showing ".01". This has been happening consistently the last couple of weeks. I'll run 3 tests and 1 is always SKY HIGH....am I doing something wrong? The only thing I can think is that I'm rinsing with tap water (the vials) and letting them air dry. Would that cause a bad reading? What gives?

 

[shwareefer]

If it's always the first test then I would think contamination of the vial. Always better to rinse with rodi and let dry inverted or just leave it full of rodi until the next use.

 

[BanjoBandito]

Gotta be contamination right?

 

[rob taft]

Sounds like contamination. After I perform my test, I rinse out the vial with RODI and then refill to the brim with RODI and cap off until I do the next test.

 

[Shirak]

Might help to describe each step you are taking. There could be something in your procedures that are giving you wonky readings.

I also rinse several times after each test with RODI and store full of RODI.

 

[kingjames_dc5]

Are you cleaning finger prints off vile before placing in tester ? I’ve found this to cause inaccuracy.

 

[Derrick0580]

Also you want to make sure you are getting as much of the reagent powder into the vial as possible. I hold the corner and flick the package several times to get everything to one corner.

 

[Ocelaris]

hmm... never had it read weird. I hate to say it, but I've found their instructions enlightening more than once.

How to Test for Phosphate in Your Aquarium

It's important to measure phosphates in a reef tank; if the levels get too high, it can prevent coral calcification or cause excessive algae growth.

blog.hannainst.com

But my procedure is flick the powder into one corner, making sure it's fully in one corner (make sure it's not stuck to the corners). Cut open, then fill with the 10 mL water. I had previously rinsed the the cuvette in sea water before testing, but I've switched to always rinsing afterwards with RO (not ro/di) now. I think a double filling with sea water sometimes helps wash away any extras.

Press the button once, wait till it says C1. After filling, I wipe any smudged fingerprints off, always aim the 10mL mark to the front. let it register the sample, remove vial, flick powder in, shake, press and hold button on tester until it does the 3 minute countdown. Then I shake the sample heavily for a few seconds, then invert the big bubble to attach to any microbubbles on the sides. Leave to sit until about a minute left, then shake gently and invert big bubble to suck up any microbubbles, and let sit inside the tester (wiped down again) for the remaining 30 seconds.

Hope that helps

 

[Derrick0580]

Also, make sure when you add your test water to the vial hold it up at eye level because the top of the water is concave. So make sure the bottom of the concaved portion is at the line and not the top edge of the water or you technically won’t have the proper amount of water in the vial!

 

[Shirak]

hmm... never had it read weird. I hate to say it, but I've found their instructions enlightening more than once.

How to Test for Phosphate in Your Aquarium

It's important to measure phosphates in a reef tank; if the levels get too high, it can prevent coral calcification or cause excessive algae growth.

blog.hannainst.com

But my procedure is flick the powder into one corner, making sure it's fully in one corner (make sure it's not stuck to the corners). Cut open, then fill with the 10 mL water. I had previously rinsed the the cuvette in sea water before testing, but I've switched to always rinsing afterwards with RO (not ro/di) now. I think a double filling with sea water sometimes helps wash away any extras.

Press the button once, wait till it says C1. After filling, I wipe any smudged fingerprints off, always aim the 10mL mark to the front. let it register the sample, remove vial, flick powder in, shake, press and hold button on tester until it does the 3 minute countdown. Then I shake the sample heavily for a few seconds, then invert the big bubble to attach to any microbubbles on the sides. Leave to sit until about a minute left, then shake gently and invert big bubble to suck up any microbubbles, and let sit inside the tester (wiped down again) for the remaining 30 seconds.

Hope that helps

I am confused by the steps you are taking. I guess if you are doing it the same way and it's working to give you consistent results. Don't the instructions say to shake for 2 minutes after adding the powder, then wipe finger prints and put back into the tester (same orientation IMO if possible) and start the 3 minute timer?