No, that's fine.
Just leave it alone.
If you really need to dip it again because the algae didn't totally die wait until tomorrow and repeat the same ratio.
Scrape the excess algae before the second treatment.
2 times isn't usually necessary, but depending on the algae, you could dip it again.
Main thing is to kill the algae, that's it.
Remove the dead algae and be happy!
Grandis.