Fridge Water Filters........Question

[mark_wpduet]

I have a Whirpool fridge that has the water filter in the grill and that indicator light indicates it needs changing after six months......My question is........This seems like a default from the manufacturer........Should I be replacing my filter when the light goes red or does the filter still have a lot of life in it? I don't mind changing and paying for new ones, I was just wondering if I'm throwing money down the drain replacing them before they need to be replaced. Thanks