Issues with Phosphate... I think.. Maybe.

[Kurant]

I'll try to keep this short.. 

IM 25 Lagoon, rock is the Walt Smith Reef Rock 2.1.. 

I have the Hanna ULR Phosphorus and Phosphate checkers. I've also been testing with the Red Sea Pro kit. I get very differing results with the 3. Hanna kits, once the Phosphorus numbers get converted, is anywhere from .12-.21. The Red Sea kit reads between .04 and .08.  I have had consistency issues with the Phosphate checker, even sometimes it reads zero. I follow the exact same testing regimen with both. Clean the cuvette's with RO water. 2 minute stopwatch.  Always shake for a few extra seconds. Full to the line. Always wipe with paper towel and put into the device at the same orientation. 

Pro kit, 13 drops. Shake. 4 drops. Shake. 15 mins. It's always consistent and consistent with what I would expect from my feeding habits and the fact I run GFO, as the number has consistently gone down since starting it. Not the case with the Hanna kits. Brown algae has all but disappeared - I tend to believe the number has trended downward simply based on that fact alone.

I do think my rock leeches phosphate as it's man made, and I've read a few posts about it doing as such. That's why I started testing. But it's hard to determine which test to believe. Some say the Hanna's are accurate, but it just doesn't make sense. 

I'm kind of at a loss on where to go from here.. 

[Tired]

Do you think you have an issue with phosphate? Honestly, it's really not important most of the time. As long as it's above 0.03ppm, to keep your corals from dying, it's probably fine. Phosphate isn't toxic at any level you could reasonably get. The worst that high phosphate will do is possibly encourage algae, and plenty of tanks have "high" phosphate and perfectly reasonable amounts of algae. An important note; don't let it get below 0.03, if you want your photosynthetic organisms to live very long. High phosphate might cause a primarily aesthetic issue, low will kill things. 

 

I'm guessing you're looking for calibration/test kit advice, and I don't have that. But hopefully this is information that's useful to you anyway. 

[Kurant]

No, not so much an issue. But the difference between .04 and .21 is quite dramatic. I'd definitely be more worried if I thought I had an issue. It's more of, I don't know if I have an issue, or will because I can't pin down what the actual number is. 

I'm definitely not number chasing, I just want to know what the number is with some sort of confidence. If there is a problem, then I'll worry about fixing it. Does that make sense? 

I did go to the LFS today, and they tested it on a 2 different Hanna checkers at .04 and .05. I'm beginning to wonder if my Hanna needs to be calibrated. I didn't do anything differently than they do, I'm far more OCD about doing the test the exact same every time then they were. Lol.  



 

[Tired]

Oh, you should absolutely have at least a semi-accurate way to tell. Have you tried repeatedly checking the same sample with the same method, to see if it varies at all test-to-test? 

But, yes, you should absolutely try and calibrate things. Not least because, if you have a tester that's off, but is always off by a reliable number, that's workable. 

[jefferythewind]

i have the red sea pro test kit and it has been reading consistently the same that i was getting on a previous test kit from aquaforrest. The accuracy seems pretty good with it. I find the color wheels very easy to read.

[Kurant]

5 hours ago, jefferythewind said:

i have the red sea pro test kit and it has been reading consistently the same that i was getting on a previous test kit from aquaforrest. The accuracy seems pretty good with it. I find the color wheels very easy to read.

I do too. 

I actually think the Red Sea Pro kits are some of my favorite in over 20 years in this hobby. I am far less impressed with the Hanna checkers.. I have 100+ reagents, plus the devices themselves, I'm in well over $100 on both.. Not ready to give up yet. Lol. 

[Kurant]

11 hours ago, Tired said:

Oh, you should absolutely have at least a semi-accurate way to tell. Have you tried repeatedly checking the same sample with the same method, to see if it varies at all test-to-test? 

But, yes, you should absolutely try and calibrate things. Not least because, if you have a tester that's off, but is always off by a reliable number, that's workable. 

Yes, sometimes between the Hanna unit's I've seen as high as .1, and that was a test done simultaneously, using the same C1 sample on both units. Do you see my dilemma now? 

It's confusing. 

The Red Sea kit started at .16 when I started with GFO. It has consistently reduced in the 4 weeks I was changing out every Saturday to .06ish. (color is between .,04 and .08.)

The Hanna's haven't done that. They've been all over the place. 

[mcarroll]

I don't think Hanna Checkers have a calibration.

 

Also, I think Tired's idea of checking your procedure got lost in the LFS story.

 

They idea was for you to take a sample of water for testing...but instead of running one Hanna PO4 test on it and then being done....run one test, then another, then another....all on the same sample.  You should be able to get VERY close results each time if not the same.  If not, you are almost surely doing something wrong.  I'll tell you right now that it's highly likely you're doing something wrong.  I think these Checker's are amazing, but their absolute requirement for attention to detail (and amount of detail) is their Achilles heel.  

 

Like a "normal" test kit, the reagents can be bad.  That is a problem both kinds of test have in common.

 

But in addition with a computer-based kit....  

You can have lint on you vial.  

You can have a fingerprint on your vial.  

You can have a water spot on your vial.  

You can have a bubble on your vial.  

You can have particulates floating in your sample.  

You can have a scratch on your vial.  

 

All of those things can have a major impact on your test results.  

 

All are pretty common.  

 

And that list was just off the top of my head.

 

That said, if you figure out what you're doing wrong, can pay strict attention to detail (and don't mind doing so), and practice....you CAN get really good with them.  

 

You certainly can't beat the level of precision you get from a digital tester when you have the process down pat.

[jservedio]

Also, after you confirm your process is correct (and math is correct - [Reading on ULR Checker] * 3.066 / 1000 = Phosphate in PPM), check your reagents for the expiration date and for the lot number. If they aren't expired and you are doing everything correct - send Hanna an e-mail with the lot number and they can tell you if there is an issue with that lot number.

[Tamberav]

You can buy hannah calibration check instruments for whatever one you are using to see if it is still working properly. 

 

https://www.saltwateraquarium.com/search.php?search_query=Hannah check set&section=product

 

 

[Kurant]

9 hours ago, mcarroll said:

I don't think Hanna Checkers have a calibration.

 

Also, I think Tired's idea of checking your procedure got lost in the LFS story.

 

They idea was for you to take a sample of water for testing...but instead of running one Hanna PO4 test on it and then being done....run one test, then another, then another....all on the same sample.  You should be able to get VERY close results each time if not the same.  If not, you are almost surely doing something wrong.  I'll tell you right now that it's highly likely you're doing something wrong.  I think these Checker's are amazing, but their absolute requirement for attention to detail (and amount of detail) is their Achilles heel.  

 

Like a "normal" test kit, the reagents can be bad.  That is a problem both kinds of test have in common.

 

But in addition with a computer-based kit....  

You can have lint on you vial.  

You can have a fingerprint on your vial.  

You can have a water spot on your vial.  

You can have a bubble on your vial.  

You can have particulates floating in your sample.  

You can have a scratch on your vial.  

 

All of those things can have a major impact on your test results.  

 

All are pretty common.  

 

And that list was just off the top of my head.

 

That said, if you figure out what you're doing wrong, can pay strict attention to detail (and don't mind doing so), and practice....you CAN get really good with them.  

 

You certainly can't beat the level of precision you get from a digital tester when you have the process down pat.

I just ran 3 tests on both the Phosphate and Phosphorus. Same procedure, same orientation in the checker. 

Phosphate all read 0.0
Phosphorus read 6 - 2 - 2

Those numbers on the phosphorus test I would assume be undetectable on the phosphate checker. Which would mean that they are consistent between the 2. Or am I off base here? 

 

[mcarroll]

6 hours ago, Kurant said:

Those numbers on the phosphorus test I would assume be undetectable on the phosphate checker.

I would actually presume the Checker has a lower detection limit along with the greater precision.

 

6 hours ago, Kurant said:

Phosphorus read 6 - 2 - 2

The differing numbers mean there's something "off" with your testing process that threw off the first test.  Unless you can pinpoint what that was, you can assume that future tests will randomly be "off" due to the same reason.

 

This is what I was saying goes down to practice.  It's not uncommon to have inconsistent results at first...dealing with the glassware properly is laborious AND error-prone IMO.  That's the price of digital precision.  Practice. Practice. Practice.  Figure out the thing(s) you're doing wrong and it'll be great. 👍  I've been able to get good with every Checker I've tried....even the Calcium Checker, which is 5X more complicated than the PO4 or alkalinity checkers.  So be patient, and practice.  👌

[mcarroll]

(If I didn't say it already, it could be worth mentioning that for speed and simplicity I ended up switching back to traditional drip tests.  Personally, I can tolerate the lack of precision.)

[Kurant]

59 minutes ago, mcarroll said:

I would actually presume the Checker has a lower detection limit along with the greater precision.

 

The differing numbers mean there's something "off" with your testing process that threw off the first test.  Unless you can pinpoint what that was, you can assume that future tests will randomly be "off" due to the same reason.

 

This is what I was saying goes down to practice.  It's not uncommon to have inconsistent results at first...dealing with the glassware properly is laborious AND error-prone IMO.  That's the price of digital precision.  Practice. Practice. Practice.  Figure out the thing(s) you're doing wrong and it'll be great. 👍  I've been able to get good with every Checker I've tried....even the Calcium Checker, which is 5X more complicated than the PO4 or alkalinity checkers.  So be patient, and practice.  👌

So, oddly enough. 

I went ahead and did the Saltwateraquarium.com testing, because I had credit and didn't need anything, I went ahead and paid the $20. I got the results back today, and their testing says my PO4 on the 5th was .09..  I was not running any media until the 10th. I will test with my Red Sea kit tomorrow AM and see. I'm curious now. Guess I do need more practice with the Hanna. I did order some new cuvettes. 

 

[mcarroll]

18 minutes ago, Kurant said:

Guess I do need more practice with the Hanna. I did order some new cuvettes. 

👍

 

Use their glass-cleaning cloth too unless you already have a nice one.  The cleaning cloth is not a good thing to skimp on.  Theirs is good and is very reasonably priced.

 

If you don't have a little squirt bottle of distilled (or RODI) water to use for cleaning, then I'd recommend that as well.  Preventing water spots is WAY easier than cleaning them.

 

I use this kind...a Nalgene™ Unitary™ LDPE Wash Bottle...

 

But I think these kind with a separate "straw" might be more common...even for watering plants and such...