Dosing sodium Phosphate

[paul.o]

My Tank is currently suffering from fairly bad cyano, latest parameters were zero phosphates and 50+ nitrates, all others were within acceptable limits. I have read that raising the phosphates should reduce nitrate and also help with the cyano.
I have got some mono sodium phosphate and looking at James planted tank calculator I need to mix 8 grams in 500 ml of water and dose 1ml (tank is 75 litres) which would add 0.15 ppm of phosphate.
Question is how often do I need to dose & check levels, dose daily and check weekly ?

 

[ScottB]

My Tank is currently suffering from fairly bad cyano, latest parameters were zero phosphates and 50+ nitrates, all others were within acceptable limits. I have read that raising the phosphates should reduce nitrate and also help with the cyano.
I have got some mono sodium phosphate and looking at James planted tank calculator I need to mix 8 grams in 500 ml of water and dose 1ml (tank is 75 litres) which would add 0.15 ppm of phosphate.
Question is how often do I need to dose & check levels, dose daily and check weekly ?

I can't speak to the math as I used a different (Trisodium Phosphate) solution. But I will suggest that it may take a lot of solution to keep a positive reading for 24 hours. In a fully depleted system, all the initial doeses will get bound to available aragonite (rock, sand).

I dosed nearly 2 liters before enough residual remained in the water column. Just FYI.

I was testing the day after dosing. Daily for a while, then weekly.