Yea... I'm not too keen on messing with acid. I'll just soak the rock, and maybe put something in the container that will pull or absorb phosphates. I wasn't planning to soak them but about 6 weeks. I'm a little concerned that you've been soaking yours for a year, and you're still seeing measurable phosphates. I'm almost regretting buying Pukani Rock now. Maybe I should have gotten something else.