with a tank your size, you could achieve more by doing some water changes. Also, your po4 is .8? Not .08? If it is .8 that is mega high! What is your alk, ca and mg? Do you dose those? nopox doesn't do as much for po4 and I think doing some big wc's would be faster for your no3.
Yeah chaeto needs light. I moved some to my aio while treating my other tank with reef flux and had a light shinning on a basket I used magnets to hold it to the sides. Not the best though as it added to the no3 due to die off in the baskets.
Because you are leaving, stop the nopox and deal with things when you get back.