I am glad to hear that you no longer send disposable water bottles to school with your kids. I remember that was a thing when I was growing up and it was so incredibly wasteful. Thankfully we’re making shifts in our thinking! I find the filter bottle option, at least for kids, may get a little bulky, especially for younger kids. Not to mention, they’re a fair bit more expensive than a reusable bottle itself (and you know how kids sometimes lose things). I recommend that rather than sending them to school with the filter bottles (which are cool for mom and dad), try sending them with filtered water in a reusable water bottle.
For convenient and quick filtration, I really like the Aquasana Clean Water Machine, which has a pitcher and a countertop dispenser for filling ease as everyone heads out the door each morning.
For a water bottle, I’ve been a longtime fan of Contigo products. They are BPA-free, durable, top-rack dishwasher safe and come in many configurations. If you prefer not to place it in the dishwasher, you can soak the bottle and bottle top in warm soapy water and scrub the mouth piece with a small bottle brush, and the bottle itself with a larger bottle brush.