Replacing gfo daily?

[slythy]

I let my phosphates get high (0.50+) in my 280 gallon system. I have been using about 7-9 tbsp of rowaphos in a reactor to bring it down but it seems like i get a drop every 24 hours then it plateaus. Is this about the expected life out of the rowaphos?

I assume my rocks are 90% phosphates at this point lol.

Thanks

 

[coralboi56]

In my experience, rowaphos does plateau in the first few days, but then it continues to do it's work. I service aquariums for a career and make it a habit to switch out rowaphos every third week of a month. That's usually the time frame I've seen where a rowaphos does has fully run it's course

 

[Randy Holmes-Farley]

The depletion rate of GFO depends on how high the phosphate is and how rapidly new water is brought to it. It may well deplete in 24 h at phosphate > 0.5 ppm.

You can measure the phosphate in the outflow from it to verify.