Phosphate testing

[BuffaloLake]

I have a 310 gallon system running the full Triton method. I have a Trident NP on the system, backed up by Hanna checkers. I had been getting wildly different results on the readings. So I recorded the Trident results, then ran 3 Hanna tests, then took a sample for an ICP. These are my readings from that test:
Trident NP 0.22
Hanna ULR Phosphate average 0.39
Triton ICP 0.07

Nitrate was also wildly different between Hanna and Trident. But I didn’t see nitrate listed on the ICP

Kinda at a loss on what I can trust.

 

[Randy Holmes-Farley Verified Community Expert]

The Triton icp may have been around a while before testing and may have growth in it that reduced phosphate. But that is just speculation. I’d just assume the tank value is near the higher values, and unless you have a reason to want to lower it, just let it ride. :)

 

[Desert•Reefer]

I have a 310 gallon system running the full Triton method. I have a Trident NP on the system, backed up by Hanna checkers. I had been getting wildly different results on the readings. So I recorded the Trident results, then ran 3 Hanna tests, then took a sample for an ICP. These are my readings from that test:
Trident NP 0.22
Hanna ULR Phosphate average 0.39
Triton ICP 0.07

Nitrate was also wildly different between Hanna and Trident. But I didn’t see nitrate listed on the ICP

Kinda at a loss on what I can trust.

I've ran into this a few times, my Hanna & Salifert results are always higher than what I get back on ICP. I'm no chemist but i've always had a suspicion that nutrients are getting consumed by the bacteria in the water on the 2 week ride to testing.

 

[Tangdora]

How consistent were your 3 Hanna test before averaging.

 

[Desert•Reefer]

How consistent were your 3 Hanna test before averaging.

"Hanna ULR Phosphate average 0.39" he did say average lol

 

[BuffaloLake]

Thank you guys, I hadn’t thought about Bacteria continuing to consume the nutrients while in transit. I tend to feed heavy, phosphate can get out of control. I don’t have a problem with nitrates, they stay between 1-20 with chaeto in fuge. But for phosphate I’ve tried GFO in bags and in a reactor, phosban, Phos-E, and Carbon dosing. Carbon dosing is actually the most effective method I have tried for reducing phosphate. Odd thing is that NoPox doesn’t seem to drop my Nitrattes at the same time., just phosphate.

 

[Tangdora]

"Hanna ULR Phosphate average 0.39" he did say average lol

I get that. There a big difference in averaging a .22, .27 and including a rogue test of .7 to arrive at a .39 average.

 

[BuffaloLake]

How consistent were your 3 Hanna test before averaging.

Not as consistent as they should be. This morning I filled two cuvettes with tank water. Added Hanna reagent to one for C2, kept the other as C1. I then ran those same samples repeatedly. Results were 0.55, 0.64, 0.56, 0.47, 0.61.

 

[BuffaloLake]

How consistent were your 3 Hanna test before averaging.

I ran 3 tests that morning with my Hanna, 0.47, 0.31, and 0.39. That’s why I said “average”, I was not including the other tests in the average, just the Hanna

 

[BuffaloLake]

I ran 3 tests that morning with my Hanna, 0.47, 0.31, and 0.39. That’s why I said “average”, I was not including the other tests in the average, just the Hanna

 

[Tangdora]

Not as consistent as they should be. This morning I filled two cuvettes with tank water. Added Hanna reagent to one for C2, kept the other as C1. I then ran those same samples repeatedly. Results were 0.55, 0.64, 0.56, 0.47, 0.61.

Typically when I see inconsistent result I would shift focus to your actual testing procedure.

1) What are you using draw your samples. Are you using the same syringe to draw tank each time. The syringes included in the kits are junk and rely on your eye to fill it to the line. If not already using should consider getting and adjustable pipette with individual tips for each solution and tank

2) How are you storing or cleaning your vial.

3) Are you flushing with RO between test