[BlueAbyss]

I have read that the iron content in these products seems to get depleted in a year or two, rendering the 'mud' relatively useless. A DSB and iron dosing would seem to be a better, more permanent option (though if you're going to dose with iron, be aware that the test kits are terribly inaccurate, and you'd be best to keep a close eye on your livestock and algaes).