for an ounce more weight.

As a backup, or if you are traveling to an area that you have to worry about viruses, than the chlorine dioxide tablets will treat more pathogens than iodine. I keep some in my PSK and my wallet. They take up little room and weigh almost nothing.

if you really prefer iodine for water purification than I would suggest carrying it in pill form for the reasons mentioned above.

I do carry some iodine pads for disinfecting wounds and you could also use them in a pinch by squeezing out drops into your water container. I've had a DEET pad develop a tear and ruin my first aid kit for a second time, lucky I guess , so I keep all strong pads in tiny Ziploc bags to protect my other gear.

Good luck with whatever method you decide to use.