Drastically different PO4 results, what to trust?

[Wiskey]

Hello all!

I have the Hanna ULR P04 checker, and for the longest time I've been measuring PO4 levels close to 1. I just opened up a new batch of regents and my first test said 0, my second one said INV, which means basically 0. I feel like one of these regent batches is bad, but I don't know which one!

Because of the high readings on the last batch, I've been tearing through Phosphate RX, rawaphos and feeding less, but it never seemed to make more than a marginal difference. Now I'm left wondering if I was getting false readings all this time.

This image of the tank is about 2 months old, back then I was reading around 1 every test:
IMG_9723 by Wiskey2727, on Flickr

Can you think of a way that I can figure out which batch was bad without having someone check it? I never get algae on the glass, only a light bacteria film after a couple days. I do have some bubble algae on the powerhead after a few months of not cleaning.

Whiskey

 

[Brew12]

Hello all!

I have the Hanna ULR P04 checker, and for the longest time I've been measuring PO4 levels close to 1. I just opened up a new batch of regents and my first test said 0, my second one said INV, which means basically 0. I feel like one of these regent batches is bad, but I don't know which one!

Because of the high readings on the last batch, I've been tearing through Phosphate RX, rawaphos and feeding less, but it never seemed to make more than a marginal difference. Now I'm left wondering if I was getting false readings all this time.

This image of the tank is about 2 months old, back then I was reading around 1 every test:
IMG_9723 by Wiskey2727, on Flickr

Can you think of a way that I can figure out which batch was bad without having someone check it? I never get algae on the glass, only a light bacteria film after a couple days. I do have some bubble algae on the powerhead after a few months of not cleaning.

Whiskey

The Hanna ULR phosphorus checker has a range of 0-200ppb phosphorus or 0-0.613ppm phosphate. So it shouldn't be possible to get a reading near 1ppm with this test kit.
https://hannainst.com/resources/aqu...phate-conversion-table--hanna-instruments.pdf

 

[mahindra.dev]

+1 on @Brew12 comments.

 

[Wiskey]

The Hanna ULR phosphorus checker has a range of 0-200ppb phosphorus or 0-0.613ppm phosphate. So it shouldn't be possible to get a reading near 1ppm with this test kit.
https://hannainst.com/resources/aqu...phate-conversion-table--hanna-instruments.pdf

Sorry,.. I meant 0.1 PPM,.. Exact readings are as follows:
1/7 - 0.21
1/16 - 0.22
1/28 - 0.13
2/11 - 0.15

-At that point, I ran out of regents and the new batch was ordered-
4/24 - 0
4/25 - 0

Thank you,
Whiskey

 

[Brew12]

Sorry,.. I meant 0.1 PPM,.. Exact readings are as follows:
1/7 - 0.21
1/16 - 0.22
1/28 - 0.13
2/11 - 0.15

-At that point, I ran out of regents and the new batch was ordered-
4/24 - 0
4/25 - 0

Thank you,
Whiskey

Just for more clarification, your actual readings on the checker were around 070 to 075 for the 0.21 and 0.22 readings?

 

[Wiskey]

Just for more clarification, your actual readings on the checker were around 070 to 075 for the 0.21 and 0.22 readings?

That is correct, when I plug that number into my Apex's log it transposes it into the actual PO4 PPM value.

Thank you,
Whiskey

 

[Brew12]

I have a hard time believing any 0ppm reading on a healthy tank however your initial readings do seem high for someone using phosphate reducers. I will say that cleaner looking tanks like yours tend to have higher phosphate than tanks with more algae since the algae can consume the available phosphate in the water.

I'm guessing you have double checked the new reagents to make sure they are for the phosphorus tester and not the phosphate tester? Shipping mistakes do happen.

 

[Wiskey]

Yeah, the new regents have to be bad,.. I contacted BRS to see if I can go through them with this, or if I need to go to Hanna themselves.

Thank you!
Whiskey

 

[Wiskey]

BRS kindof gave me the brushoff saying that they rarely have problems with Hana Regents and I should add some phosphate to the sample and test again and if I still feel there's an issue they will get me in touch with Hanna. It was clear that they were not willing to assist so I went to Marine Depot and ordered another set. They read perfectly.

Beware of sudden 0 readings,.. it looks like there could be a bad lot out there.

Whiskey

 

[skim]

One thing to remember and I find this a lot when people use test kits. These are not Lab grade and some are better then others, the Hanna unit is quite good but still will you only give an idea of what is going on and not a absolute. If you do not have an Algae issue then I would not waste the time and money on replacing the Regents, just make sure you some on hand when needed. Spend time enjoying what you have created and not looking for issue, because they will come. If you spend all your time looking for and testing and an issue or two come when did you get to enjoy your creation. Your best investment and best test kit is your EYES! Use them and them well.
If you must test, the I would say invest in one of the units you send away and then receive a report on. What it cost to buy and use some of the home units you may be able to send a sample quarterly.

 

[Reefer1978]

Just figured I ask - reagents weren't expired? I did a few tests myself last weekend - reagents that expired in Jan - 0.1ppm, reagents expiring next month - 0.06ppm.

 

[Wiskey]

Nope,.. they expired in 2019 sometime. I reached out to Hanna and they were awesome! They got right back to me and are going to send out a new batch.

Whiskey