Peroxide fresh water

I forgot to dump my fresh water tank on our last outting. Been sitting at least 1/2 full in my driveway since, which has been 2 weeks.

I would have just drained it but my driveway slopes forward so iit wouldnt get empy anyhow.

If i dump some peroxide in today and soak until wednesday and then flush, is that a problem for any reason?