Drilling a nano and bulkhead sizing

[Ahogue21]

Now that my main tank is up and running the plan has been to add in a mini tank next to the sump in this case a mini clear 10

Plan is an overflow and 2 drains a reg and emergency now currently i have a drill for a .5in bulk head.....am i asking for trouble with a 2 .5 in bulk head drain setup?

Plan was a life guard grate on it so somthing cant plug up the entire drain or should i be upping the size to 3/4? I dont think flow will be an issue

And pics....lighting setup is temporary waiting on the parts to build my light rack

 

[SPR1968]

I can’t help with the specific question but I can bump the thread to see if we can get you some help