Has anyone out there ever heard of a product called "cleanwater"?  It is
marketed in the US by Penn-Plax, but is made by a company in the
Netherlands by the name of "C.R. Products".  It claims to remove the

Phosphate =  3.5 g/kg of cleanwater
Nitrate   =  13 g/kg of cleanwater
Nitrite   =  10 g/kg of cleanwater

It also states that it will keep your tank clean for up to 3 months.  

Thank you for your help.