phosphate binding capacity of steelwool

Tmmste · Aug 31, 2019

I use steelwool only to reduce Po4, the rust is mechanically removed. I wondered how much Po4 is bound per gram of steelwool. I use 0,8/1gr per 400l to remove 0,04ppm.. however, last time I needed 8gr within 1 week.. to reduce Po4 from 0,12 to 0,08. So I think 0,36 ppm leached from my rockwork..but I am not sure as I do not know exactly what the binding capacity of steelwool is. Hopefully someone knows..

Randy Holmes-Farley · Aug 31, 2019

I'm not a fan of this due to impurities in the iron, and there cannot be any exact calculation as you do not know what form the iron will take, but IF all the iron ended up as ferric phosphate (FePO4) then it binds 1.7 times the iron weight as phosphate.

The rockwork calculation is also complicted by feeding during the week, assuming there was any.

Tmmste · Sep 1, 2019

Randy Holmes-Farley said:
I'm not a fan of this due to impurities in the iron, and there cannot be any exact calculation as you do not know what form the iron will take, but IF all the iron ended up as ferric phosphate (FePO4) then it binds 1.7 times the iron weight as phosphate.

The rockwork calculation is also complicted by feeding during the week, assuming there was any.

Alright thank you for your reply. I use a very pure source of steelwool (metalino), but it is a good idea to do a triton test and see if any heavy metals accumulated.