How much GFO to use to reduce phosphates?

[flyhigh123]

I have about 100 gallon water volume.

Current phosphate levels are 1, which is really high.

i have bulk supply GFO. How much should i use and how long would it take to reduce the levels to 0?

Should i use it all at once or switch it out? How often should i switch it out?

thanks

[Toddrtrex]

I would start off slowly --- too much GFO too soon can drop your Alk levels, which will cause you additional issues.

With a phosphate reading of 1, it is going to use up the GFO fairly quickly, and might take a while to get down to acceptable levels.

What reactor are you using? If you are using the two little fishes Phosban reactor I would say maybe sort off with about an inch, and maybe change it out after 2 weeks. But, keep testing your phosphates -- that will help determine when to change it out -- and keep an eye on your Alk levels.