I'm one of those people always keeping an eye out for filters... 20x25x1, all brands. I picked up the FILTRETE 1500 healthy living, electro static filters with the purple and white label, with the family sitting on the stairs.
It's SO easy to pop in and take out. Just a dream compared to all other brands, the last which I stuffed unceremoniously INTO the slot, knowing I'd forked it up.
I think the cardboard is sturdier, but also it seems to be a tad more petite.
If you're struggling with too tight filters, consider checking out this brand... best deal I found was at Walmart.
They're expensive, but supposed to last up to 3 months. I change every 4-6 weeks bc the system will last longer, or so I'm told. I think I ended up paying under 14.00 per unit, and they're over 20.00 each on some sites.
Lighter
