Nitrate in the tank, testing and dosing q's

Hi Kara,

First, I think You are putting way too much faith in the accuracy of these hobby grade test kits. Your reading is well within the margin of error. I'm not saying that You didn't, but the instructions on the AP Nitrate test kit have to be followed to a Tee---otherwise: Each test that's not completed correctly screws up every other test left in the kit. It says to shake solution #2 for 30 seconds--that's a minimum and very, very important. Then shake the test tube for a full minute--That's a minimum too. Then read the test kit at 5 minutes--not after 5 minutes. Again, I'm not saying or suggesting that You didn't follow the instructions, its simply that others will come along and read this too. Even following the instructions--Your reading is within the margin of error for that grade test kit.

Also, there's a number of possible reasons that Your nitrates may be accumulating. One maybe the Plant Gro. I started out using Plant Gro and ultimately it didn't do the trick. You may want to head over to Rex's and pick up the basics: Ferts

You'll be able to dose with greater precision and more folks will be able to help You with problems.

As for testing Your test kit: There's a thread or 3 around here some where that lists how to make the solutions--but You won't be able to do it with the Plant Gro. Here's a couple of items that might help (You'll need KN03):

NO3
KNO3 - 20 gram in 500 ml

2 ml in 10 litre = 5 ppm
4 ml in 10 litre = 10 ppm
8 ml in 10 litre = 20 ppm
12 ml in 10 litre =30 ppm
16 ml in 10 litre = 40 ppm
20 ml in 10 litre = 50 ppm



NO3
KNO3 – 33 gram in 500 ml (or #1 Solution by PPS-Pro)

25 drops in 10 litre = 5 ppm
2 ml and 10 drops or 50 drops in 10 litre = 10 ppm
5 ml in 10 litre = 20 ppm
7 ml and 10 drops in 10 litre = 30 ppm
10 ml in 10 litre = 40 ppm
12 ml and 10 drops in 10 litre = 50 ppm

HTH

Once the CO2 is up and running you may dose at 1/2 teaspoon of KNO3, which is equal and fairly accurate to about +/- 1-2ppm of NO3 over 10 trial runs.
Or about 3.35 grams.

That will add about 9-10ppm per dose of NO3 and 4-5ppm of K+ for the tank you have. Due to sand, rock and other things other than water, it'll tend to be a tad higher.

You can add the fert salts to water and add mls, some find this useful for their habits and for smaller tanks it can improve accuracy.

You can also divide the dosing routine over 7 days a week, daily dosing etc, or 3x a week if you want also.

I'd not go below 3x a week for most dosing routines with CO2.
Lower light will allow more flexibility with CO2 and dosing though.

Regards,
Tom Barr

pittiepride said:

...I am analytical by nature so completed the test to the best of my abilities (I am a water quality analyst by trade but I still have to pay for tests so I do not get it done at work lol)...

Kara

Click to expand...

Hi Kara

I wrote up the solutions to make so that you can calibrate your NO3 and PO4 test kits. I hope that this helps you.



How to Make Reference NO3 and PO4 Solutions

Here's a way to make 10, 20, 30 and 40 ppm NO3 reference solutions:

Add 1.631 g of KNO3 to 1 L DI/RO water. This makes a 1000 ppm NO3 solution. (It's really a 1000.29 ppm solution.)

Add 2 mL of the 1000 ppm solution to 18 mL of DI/RO water. This makes 20 mL of a 100 ppm NO3 solution.

Add 15 mL of the 100 ppm solution to 15 mL of DI/RO water. This makes 30 mL of a 50 ppm NO3 solution.

To make a 10 ppm NO3 solution:
Add 2 mL of the 50 ppm solution to 8 mL of DI/RO water. This makes 10 mL of a 10 ppm NO3 solution.

To make a 20 ppm NO3 solution:
Add 4 mL of the 50 ppm solution to 6 mL of DI/RO water. This makes 10 mL of a 20 ppm NO3 solution.

To make a 30 ppm NO3 solution:
Add 6 mL of the 50 ppm solution to 4 mL of DI/RO water. This makes 10 mL of a 30 ppm NO3 solution.

To make a 40 ppm NO3 solution:
Add 8 mL of the 50 ppm solution to 2 mL of DI/RO water. This makes 10 mL of a 40 ppm NO3 solution.




Here's a way to make 1.0, 2.0, 3.0, 4.0 and 5.0 ppm PO4 reference solutions:

Add 1.433 g of KH2PO4 to 1 L DI/RO water. This makes a 1000 ppm PO4 solution. (It's really a 1000.09 ppm solution.)

Add 1 mL of the 1000 ppm solution to 9 mL of DI/RO water. This makes 10 mL of a 100 ppm PO4 solution.

Add 2 mL of the 100 ppm solution to 18 mL of DI/RO water. This makes 20 mL of a 10 ppm PO4 solution.

To make a 1.0 ppm PO4 solution:
Add 1 mL of the 10 ppm solution to 9 mL of DI/RO water. This makes 10 mL of a 1.0 ppm PO4 solution.

To make a 2.0 ppm PO4 solution:
Add 2 mL of the 10 ppm solution to 8 mL of DI/RO water. This makes 10 mL of a 2.0 ppm PO4 solution.

To make a 3.0 ppm PO4 solution:
Add 3 mL of the 10 ppm solution to 7 mL of DI/RO water. This makes 10 mL of a 3.0 ppm PO4 solution.

To make a 4.0 ppm PO4 solution:
Add 4 mL of the 10 ppm solution to 6 mL of DI/RO water. This makes 10 mL of a 4.0 ppm PO4 solution.

To make a 5.0 ppm PO4 solution:
Add 5 mL of the 10 ppm solution to 5 mL of DI/RO water. This makes 10 mL of a 5.0 ppm PO4 solution.