x2 holes on lid

[gary007]

hi, one on of my tanks, on the lid it has x2 pre drilled holes, im guessing its for external filter yea care to share do i need to drill holes a bit larger so those tubes can go through lid to tank yea cause those x2 pre drilled holes are so tiny.

[Radiance]

I believe those two tiny holes serve 2 functions:

Easier for you to start cutting/sawing out a section of the lid to accommodate your filtration device. They do this so you can cut the right sized hole just big enough for your device, preventing your fish from jumping out. Also reduces evaporation.

The other is for airlines. the hole is just big enough for the tubing, preventing the bubbles from spraying water all over the top of your tank.