If you're using household ammonia to cycle your tank, here's how to calculate how much household ammonia to add in order to get the desired ppm NH3.
Desired tank ammonia level/ (Ammonia concentration % (from the label) x 10/tank volume in litres) = Amount of household ammonia to add in ml
Here's an example:-
Tank volume = 165litres
Ammonia concentration % = 9.5 (from the label on the bottle)
Desired tank ammonia level in ppm= 4
So,4/(9.5x10/165)=ammonia ml to add.
4/(95/165)=ammonia ml to add
4/0.58=ammonia ml to add
=6.9 ml household ammonia
Actually we don't need to be that accurate, so let's call that 7ml.
In other words adding 7ml of household ammonia to this example tank will result in an ammonia NH3 concentration of approximately 4ppm. Which is what we want.
Once your cycle is up and running, it is likely that you will only need to 'top -up' the ammonia. In that case if your tank ammonia level was already 2ppm, then 'desired tank ammonia level' in the example above would also be 2ppm, in order to maintain the desired overall tank ammonia level of 4ppm.
Note:
When I worked mine out for 100L of actual water the tank holds it came back as 4.2ml. When I first dosed the tank it was 5ml. then when i dosed there after I atleast added 1ml. Now I believe I may have been overdosing my tank from the start!
btw I found this on the PFK forum
