Help me create a Nitrate Reference Solution

[TheDuude]

Hello all,

Hoping someone can help me out here as I am not finding what I am looking for with a google search.

This weekend I purchased a new nitrate test kit.

Current test kit ( NYOS ) is reading 3 ppm nitrate and has been fairly consistent over the last 2 months or so ( I am dosing Kno3 to maintain Nitrate )

New test kit ( Salifert ) is reading 100 PPM! I am fairly certain I am reading the Salifert test correctly. The color comes out a very dark pink.

So at this time, I am assuming the Salifert test is bad but I have been dosing rather large amounts of Kno3 to keep my Nitrates up so they could certainly be that high and the NYOS reading wrong.

Can anyone tell me how to make a Nitrate reference solution? I have RODI water and powdered Kno3 from Green Leaf Aquariums but cannot seem to find a formula to make a low range reference solution.


Thanks!

 

[Randy Holmes-Farley]

How low are you talking about? Do you have a scale?

In the absence of high end tools, you will need to assume some new salt water is 0 ppm nitrate, and then you could do, say 5-10 ppm nitrate standard OK. Doing 2 ppm or less will be problematic due to that assumption.


Pure potassium nitrate is 13.85% nitrogen. Your product claims it is 13.7%, so may have moisture in it.

You can use this calculator to determine how much to add, and then possibly correct for the possible moisture in your product.:

James' Planted Tank - Dosing Calculator

 

[TheDuude]

5 to 10 would be fine.. Ideally, I want something above 3 to make sure my NYOS kit has been reading accurately.

I do have access to a fairly decent scale in my Millipore lab at work. Should I dry the kno3 prior to try and remove the moisture?

Also taking a look at that calculator I wanted to clarify one thing.. If I make a solution with 1 gram of Kno3 powder to 10 ML of water would I then need to add that solution to 1 Gallon prior to testing or is it the solution itself that will be around 16ppm?

Thanks in advance for the help Randy!

 

[Randy Holmes-Farley]

Yes. You could also do it as 1 g in 100 mL Ro/DI, then add 10 mL to 1 gallon seawater to get 16 ppm if you do not have good 1 mL pipettes.

Drying couldn't hurt.

 

[TheDuude]

Well now I have something to do this evening!

Thanks again.

 

[homer1475]

I've used that calc! It's the actual solution, no need to dilute it.

With those mixing direction, each 1ML of mixed solution(1g, in 10ML of ro/di) will yield 16.2ppm nitrate.

 

[Randy Holmes-Farley]

I've used that calc! It's the actual solution, no need to dilute it.

With those mixing direction, each 1ML of mixed solution(1g, in 10ML of ro/di) will yield 16.2ppm nitrate.

You mean after diluting in a gallon of tank water, right?

1 g KNO3 (containing 613 mg of nitrate) in 10 mL of RO/DI is hugely higher. About 613 mg/11 g total = 55,700 mg/kg (ppm).

 

[TheDuude]

Makes more sense to me that you would need to dilute the solution as if it were being added to an aquarium.

 

[homer1475]

Ahh yes after diluting, Sorry missed the 1Gallon at the top.

I always used my tanks volume and added it to that, forgetting the dilution ration. DUH!

So you would take the mixed up solution, add 1ML to 1G of water, then test that 1G at 16.2ppm.

 

[TheDuude]

Ahh yes after diluting, Sorry missed the 1Gallon at the top.

I always used my tanks volume and added it to that, forgetting the dilution ration. DUH!

So you would take the mixed up solution, add 1ML to 1G of water, then test that 1G at 16.2ppm.

Yes thats the plan

 

[Rybren]

You could always take the lazy man's route and buy a bottle of Fauna Marin Multi-Reference solution...

https://www.bulkreefsupply.com/fauna-marin-multi-reference-solution.html

 

[Courtney Aldrich]

Hello all,

Hoping someone can help me out here as I am not finding what I am looking for with a google search.

This weekend I purchased a new nitrate test kit.

Current test kit ( NYOS ) is reading 3 ppm nitrate and has been fairly consistent over the last 2 months or so ( I am dosing Kno3 to maintain Nitrate )

New test kit ( Salifert ) is reading 100 PPM! I am fairly certain I am reading the Salifert test correctly. The color comes out a very dark pink.

So at this time, I am assuming the Salifert test is bad but I have been dosing rather large amounts of Kno3 to keep my Nitrates up so they could certainly be that high and the NYOS reading wrong.

Can anyone tell me how to make a Nitrate reference solution? I have RODI water and powdered Kno3 from Green Leaf Aquariums but cannot seem to find a formula to make a low range reference solution.


Thanks!

So what did you find out? Is the Salifert test kit overestimating?

 

[Randy Holmes-Farley]

Anyone who is really interested in understanding nitrate levels and nitrate testing should be sure they understand the sorts of issues discussed in this thread:

Nitrite In 7 Year Old System

I took @Lasse advice and started to test my system for NO2 and what do you think I found? I measured 0.05-0.1 ppm NO3 (the level varies). I am using the Hanna Total Chlorine Checker to measure the color intensity and Red Sea.. It is really there. Lasse what does it mean??? Snails, sea star...

www.reef2reef.com

 

[TheDuude]

So what did you find out? Is the Salifert test kit overestimating?

NO I ended up having a bad Nyos kit. Nyos was testing at 3 PPM nitrates when in reality I had dosed my tank up too 150+ PPM Nitrate. Confirmed with Salifert, API, Red Sea, and Reference solution. I have been working my way back down and am now at 30 PPM. Nyos kit cost me some nice SPS frags due to the no3 overdose.

 

[Courtney Aldrich]

NO I ended up having a bad Nyos kit. Nyos was testing at 3 PPM nitrates when in reality I had dosed my tank up too 150+ PPM Nitrate. Confirmed with Salifert, API, Red Sea, and Reference solution. I have been working my way back down and am now at 30 PPM. Nyos kit cost me some nice SPS frags due to the no3 overdose.

Thanks so much for responding. I was reading 100 ppm on my Salifert test kit after my tank cycle (with dry rock and Dr. Tim's method) and thought perhaps the test kit was mis-reading.

 

[reeferKen]

Anyone know if the Fauna Marin Multi-Reference solution will work on The Hanna checkers? Glad you found the problem OP Thanks

 

[Randy Holmes-Farley]

Thanks so much for responding. I was reading 100 ppm on my Salifert test kit after my tank cycle (with dry rock and Dr. Tim's method) and thought perhaps the test kit was mis-reading.

It still might be if you have any nitrite.

 

[Courtney Aldrich]

It still might be if you have any nitrite.

I tested for nitrite using an old Salifert test kit and it read 0. I purchase a new kit (exp date 9/2023) and also read 0.

 

[LongBeachReefer562]

You mean after diluting in a gallon of tank water, right?

1 g KNO3 (containing 613 mg of nitrate) in 10 mL of RO/DI is hugely higher. About 613 mg/11 g total = 55,700 mg/kg (ppm).

Hi Randy, I'm making some nitrate standard solutions for testing purposes and I wanted to make sure I'm going about this correctly...

I'm using NaN03 and my plan to create the solution is to take 1000ml of RODI and add 1g of NaN03 which I believe would contain 730ppm of N03, or in other words 7.3ppm/ml solution. Is this correct?

Also from here I would just just use C1 x V1 = C2 x V2 (solution 1 would be the N03 solution and solution 2 would be new saltwater) to calculate out the standard solutions...am I going about this correctly?

appreciate your help!!

 

[Courtney Aldrich]

Yes, I double-checked your calculation and the amount of nitrate is correct (730 mg of nitrate in 1 g of NaNO3), which provides 730 ppm when added to 1 L of water. Yes, the good old C1 x V1 = C2 x V2 is the way to go to determine the dose for your tank. I think most people overestimate their tank volume, so I would recommend reducing your tank volume by 20% to accommodate for rock and overestimates on sump and tank volume (e.g. I just measured the volume on my 20 long and it only takes ~17 gallons to fill to the rim).