Rowaphos dosage

[do not smoke the reef(er)]

Hey everyone 

 

Using Rowaphos for the first time. What is the proper calculation to use? How much should I use for my aquarium ?

 

 

Wanted to get phosphate down a little bit. Used my Hanna checker and it currently reads at 0.05 ppm. I have a 20 gallon tank (18 gallon including rock, sand,equipment) 

 

Dirextions on container were not too clear. Any helps appreciate. 

Thanks in advance everyone!

[romperstomper]

works best in a reactor with a very light tumble on the surface I use 1-2 inches and change only when po4 starts to show a reading above 0.008 ,mine last for 4- 6 months although many seem to change it very often .