Corax, I do not agree with you, Not everyone needs to have canisters. I do not have a problem servicing my HOB's weekly. I feel that i have a better handle of the condition of my tanks when servicing weekly vs monthly as with canisters. I'm also not a fan of the multiple connections that could fail vs a unit that is self contained. I'm not bashing canisters but i do feel for some people and applications HOB may work better.