HC GFO. How much does one pound amount to.

[ScubaSteve]

I just weighed some of mine for you and it dials in at 220g per cup (250ml)... So call it roughly half a pound per cup. When first adding HCGFO to a system I use roughly 1 tbsp per 8 gallons (so for you that is roughly 150ml or 0.5 cups). You could even go with a bit less. After 4-8 weeks, add another 150ml (so that you're running 2 tbsp per 8 gallons). Err on the side of too little than too much. You can easily shock your tank with this stuff. I accidentally killed off a few SPS colonies when I first started using it because I used just a bit too much.