HYDRA DEVOUR (Grain size 0.5-2.0MM) 500g Removes Phosphates, Silicates and Heavy Metals in Aquariums for Fixed or Fluidised Bed Filters

This is good GFO. I used it in marine aquarium when i had a phosphate spike.my phosphate readings where 0.08ppm and this stuff brought it down to 0.04ppm in two days and i fully expect it to bring the levels down to 0, (I will update this review if it doesn't) can i suggest if your going to use this in a reactor as i did buy the 2-4mm grain size it's just about perfect.so yea, in conclusion GFO without all the brand bull****

Will come back and make it 5 Stars if it lives up to expectations. So far, so good.