Okay, so a real quick recap. I bought some Fish Bendazole on the net.
The container came with 3 packets in it. Each packet held 250mg.
I poured out the powder from a single pouch onto glass and using a razor blade, split the powder into roughly two equal halves. This gave me roughly 125mg to use to dose my tank with.
I used a small container, scooped some water from my 10g tank and mixed the 125mg powder with the water, then poured it into my tank, and turned off the light since it is light sensitive.
I waited three days. Most planaria gone, but I still saw some occasional ones on the glass. I then dosed a 2nd time without any water change figuring if the planaria that survived were strong enough to survive the first dose, then any powder still active combined with the 2nd dose would be stronger yet and knock them out.
The 2nd dose did it. After three days I didn't see anymore planaria and did a 20% water change.
An interesting side note, I had a 10g project tank that I noticed a good amount of hydra in and used a quarter of a packet. ~63mg and the hydra have retracted their tentacles and have turned into little balls. Still waiting on a final verdict, but it's nice to know the packets can be stretched out if needed.