OK, it's green, the fish are alive. But the whole stonage has been ruining 
my tank for ages.

I'll admit, I don't keep 100% to the rules of changing the water all the 
time. But my tank is looking too green and yellow on the gravel.

Maybe I shouldn't keep fish. But they seem to be quite chilled.

I'm thinking I'll empty out the whole tank, clean the stones etc and try and 
keep the fish happy.

But keep 60% of the water. How do you do a major clean on the little stones? 
Should I buy a cheap saucepan and boil the stones clean?