Starting Trisodium Phophate and Calcium Nitrate dosing, need help with recipe

[kishstl]

As my tank is growing I'm fighting with very low phosphate and nitrate. I have been feeding more and adding reef roids and AB+ but still have very low numbers. Just received my Na3PO4 and Ca(NO3)2 from Loudwolf. I have looked for a calculator/recipe but can't find one for these reagents. Any help would be appreciated. approx 85 gal water volume and almost undetectable values for both.

Thanks!!!

P.S. Also dose Kalk through ATO

 

[Randy Holmes-Farley]

As my tank is growing I'm fighting with very low phosphate and nitrate. I have been feeding more and adding reef roids and AB+ but still have very low numbers. Just received my Na3PO4 and Ca(NO3)2 from Loudwolf. I have looked for a claculator/recipe but can't find one for these reagents. Any help would be appreciated. approx 85 gal water volume and almost undetectable values for both.

Thanks!!!

As a rough guide, you can use this calculator and the entry for phosphate from potassium phosphate and nitrate from potassium nitrate. The values will be close enough for our purposes.

James' Planted Tank - Dosing Calculator

www.theplantedtank.co.uk

Corrections are not needed, but if you did want to correct the calculated dose, the nitrate dose will use about 81% of the recommended dose to the tank.

The phosphate correction is not worth bothering with since so much gets bound to rock and sand anyway.

 

[kishstl]

Perfect. I looked at that one but didn't know if the amounts would be the same.

THANKS!!!

 

[GuppyHJD]

As a rough guide, you can use this calculator and the entry for phosphate from potassium phosphate and nitrate from potassium nitrate. The values will be close enough for our purposes.

James' Planted Tank - Dosing Calculator

www.theplantedtank.co.uk

Corrections are not needed, but if you did want to correct the calculated dose, the nitrate dose will use about 81% of the recommended dose to the tank.

The phosphate correction is not worth bothering with since so much gets bound to rock and sand anyway.

Hello Randy,
I am using Sodium Phosphate Dibasic (2 tsp in 1 gallon RODI) dosed at 10ml to raise my phosphate 0.05 ppm per the calculator above. When I test, I am still getting a 0.0 reading using a Salifert Phosphate test. I cannot use the Hanna Phosphate checker because I have high silicate in the tank. Is there a concern with adding too much of the phosphate at a time to the tank? Can I double my dose to 20ml and test an hour later etc.?
Thank you

 

[JGT]

Seems like the accuracy of the calculator isn’t that precise but I guess close enough for dosing purposes.
If I select 250 US GALS, Potassium phosphate into 1892 ml of water (1/2 gal) and want to raise PO4 by .01 ppm, adding anywhere between 2 and 5 teaspoons yields the same .01 ppm results. So then do you use 2 or 5?

 

[Randy Holmes-Farley]

Hello Randy,
I am using Sodium Phosphate Dibasic (2 tsp in 1 gallon RODI) dosed at 10ml to raise my phosphate 0.05 ppm per the calculator above. When I test, I am still getting a 0.0 reading using a Salifert Phosphate test. I cannot use the Hanna Phosphate checker because I have high silicate in the tank. Is there a concern with adding too much of the phosphate at a time to the tank? Can I double my dose to 20ml and test an hour later etc.?
Thank you

Yes, I'd add more.

Using the Hanna, what do you get? If there is an effect from the silicate, the response will be reading too high, not too low, so a low phosphate reading still means too low.

 

[Randy Holmes-Farley]

Seems like the accuracy of the calculator isn’t that precise but I guess close enough for dosing purposes.
If I select 250 US GALS, Potassium phosphate into 1892 ml of water (1/2 gal) and want to raise PO4 by .01 ppm, adding anywhere between 2 and 5 teaspoons yields the same .01 ppm results. So then do you use 2 or 5?

Yes, it cannot read to better than 0.01 precision. So it rounds the answers to the nearest 0.01 ppm phosphate.

If you want better precision, you can input 10x as much for one of the entries (such as volume dosed) and then divide the answer by 10.

Doing this, I can see that for 3 teaspoons, 10 ml dosed gives 0.08 ppm, 4 teaspoons gives 0.1 ppm, and 5 teaspoons gives 0.13 ppm. Diving all of them by 10 shows that 4 teaspoons will give 0.01 ppm. The others are above or below 0.01 ppm.

Bear in mind this can only estimate what is added, not how much will remain after much of it binds to rock and sand.