PO4 testing

[PeterEde]

I have had high nitrate (60ppm+)for quiet a while which I am struggling to get under control.
I have been dosing NOPOX 3ml daily with weekly WC. Nitrate still climb.
My last ICP had PO4 at .1ppm but after dosing NOPOX I tested PO4 at zero(undetectable) so have been dosing Triton Phosphorus at .1-.2 ml per day and testing. Still my tests shows zero/undetectable. I assume because NOPOX is working to reduce it and it stalls again once PO4 is zero and Nitrate climbs again.

I have lost a couple of corals in the last 2 weeks (Duncan/Hammer) and now wondering if my PO4 test kit has has failed me (NYOS)

I am thinking to do a test on RODI water with a drop of phosphorus into 1 liter. This should give me a good hard blue on the NYOS test. If not I can assume the kit has failed.

Does this sound a reasonable approach to discount a questionable test kit?
This is what I have been dosing as advised by LFS

 

[Woodyman]

I have had high nitrate (60ppm+)for quiet a while which I am struggling to get under control.
I have been dosing NOPOX 3ml daily with weekly WC. Nitrate still climb.
My last ICP had PO4 at .1ppm but after dosing NOPOX I tested PO4 at zero(undetectable) so have been dosing Triton Phosphorus at .1-.2 ml per day and testing. Still my tests shows zero/undetectable. I assume because NOPOX is working to reduce it and it stalls again once PO4 is zero and Nitrate climbs again.

I have lost a couple of corals in the last 2 weeks (Duncan/Hammer) and now wondering if my PO4 test kit has has failed me (NYOS)

I am thinking to do a test on RODI water with a drop of phosphorus into 1 liter. This should give me a good hard blue on the NYOS test. If not I can assume the kit has failed.

Does this sound a reasonable approach to discount a questionable test kit?
This is what I have been dosing as advised by LFS

I don't know about the Nyos specifically, but the Hanna for example is designed to test within salt water only. The test will not perform properly in RODI or freshwater.

 

[Reffetsevla]

I would test with a reagent and measure amount like you're thinking. So if you have a mixture you know should be 0.1 or w/e, use that to verify the test. Use fresh mixed saltwater though.

I recently had my API tests read zero's AFTER I started dosing Flourish Phosphourus, because of said zero's. Got myself a hanna....my PO4 was .84. I did three tests and used a seperate reagent batch to verify, it was correct. My duncan's and frogspawn were the first to really show me something was off. Everything else was Zoanthid or Palythoa which didn't care too much. Duncan tendrils looked like little balloons. Once I got PO4 under 0.1 everything went back to normal.

My experience, absolutely verify your test if you think it's faulty, your tank will tell you if something's amiss. Don't ignore it in favor of a test IMO

 

[Woodyman]

I don't know about the Nyos specifically, but the Hanna for example is designed to test within salt water only. The test will not perform properly in RODI or freshwater.

Instead I would recommend you test your water as is. Then spike it by a known amount (1 ppm for example), and see if it lines up. Just make sure your math is correct for the volume you intend to spike. Performing a a replicate of 3 for each would be ideal to account for slight variations within your testing.

 

[Reffetsevla]

Instead I would recommend you test your water as is. Then spike it by a known amount (1 ppm for example), and see if it lines up. Just make sure your math is correct for the volume you intend to spike. Performing a a replicate of 3 for each would be ideal to account for slight variations within your testing.

Spike the sample, not the tank. Just in case that wasn't clear lol

 

[Woodyman]

Spike the sample, not the tank. Just in case that wasn't clear lol

Yes the sample!

 

[PeterEde]

I don't know about the Nyos specifically, but the Hanna for example is designed to test within salt water only. The test will not perform properly in RODI or freshwater.

yeah I thought about that after posting. Easy enough to mix up a liter of salt

 

[PeterEde]

Instead I would recommend you test your water as is. Then spike it by a known amount (1 ppm for example), and see if it lines up. Just make sure your math is correct for the volume you intend to spike. Performing a a replicate of 3 for each would be ideal to account for slight variations within your testing.

Problem is how much to spike in 1 liter using .1ml graduated 1ml syringe as per titration tests?
How much is one drop? .01ml?

 

[gbroadbridge]

I have had high nitrate (60ppm+)for quiet a while which I am struggling to get under control.
I have been dosing NOPOX 3ml daily with weekly WC. Nitrate still climb.
My last ICP had PO4 at .1ppm but after dosing NOPOX I tested PO4 at zero(undetectable) so have been dosing Triton Phosphorus at .1-.2 ml per day and testing. Still my tests shows zero/undetectable. I assume because NOPOX is working to reduce it and it stalls again once PO4 is zero and Nitrate climbs again.

I have lost a couple of corals in the last 2 weeks (Duncan/Hammer) and now wondering if my PO4 test kit has has failed me (NYOS)

I am thinking to do a test on RODI water with a drop of phosphorus into 1 liter. This should give me a good hard blue on the NYOS test. If not I can assume the kit has failed.

Does this sound a reasonable approach to discount a questionable test kit?
This is what I have been dosing as advised by LFS

Don't forget that your rock and substrate will sequester phosphate, so you actually have to add quite a bit of phosphate until the rock is at equilibrium with the water column.

 

[PeterEde]

Don't forget that your rock and substrate will sequester phosphate, so you actually have to add quite a bit of phosphate until the rock is at equilibrium with the water column.

Since I have been dosing .1-.2 ml daily for a week and have now lost 2 corals in that time have I added too much is my concern? Or is it still so low corals have died due to lack of?

Do I buy a Hanna checker ? Which one to buy? Phosphate or Phosphorus. Just watched BRS video on the 2 testers. There's a conversion for phosphorus to phosphate

 

[Reffetsevla]

Since I have been dosing .1-.2 ml daily for a week and have now lost 2 corals in that time have I added too much is my concern? Or is it still so low corals have died due to lack of?

Do I buy a Hanna checker ? Which one to buy? Phosphate or Phosphorus. Just watched BRS video on the 2 testers. There's a conversion for phosphorus to phosphate

Get the ULR one where you have to actually calculate. The goal is usually .05'ish. Which the "normal" checker has a +/- of .04. So if you test at .03, you could actually be 0 given the variance. I did not realize this myself until after I ordered mine, learn from my mistake lol

 

[PeterEde]

So I tested water as per normal. Po4 undetected
Added 1 drop to 10ml and it went very blue so I'm guessing the test kit is fine and I'm just not dosing enough to over come binding.

I have instruction from Triton that say 1ml of phosphorus will add .1mg/l to 100 liters.

Question is this ok in one dose?
I have been adding only .1 -.2 ml per day

 

[gbroadbridge]

So I tested water as per normal. Po4 undetected
Added 1 drop to 10ml and it went very blue so I'm guessing the test kit is fine and I'm just not dosing enough to over come binding.

I have instruction from Triton that say 1ml of phosphorus will add .1mg/l to 100 liters.

Question is this ok in one dose?
I have been adding only .1 -.2 ml per day

I'd dose 0.1ppm - my tank get up to that when the GFO is on the way out and it doesn't harm anything Short term.

It'll probably get taken up by the rock.