Drain system

[MAGNA]

Hi guys,
I am new to the forum and want to change my drain system to the sump. I read lot of topics and not sure about the system which is the best for my 300 gallons.
I have 2, 2'' holes on the bottom of my tank on the corners.
My plan is to use one of them as an emergency and the other is for the durso system. Will it be ok or do you prefer something else?

 

[aquaman67]

[welcome]

I would use both, with lower flow so that one will cover the other in an emergency but will be used all the time.

 

[MAGNA]

Thank you for the quick reply aquaman67
But in the calculation area it said that 2'' hole will cover about 2000 gallons. So the durso for a 2'' hole will be enough and silent for my tank? Because I want to use the emergency 2'' hole only the water will be higher according to the snails or etc. And the overflow is about 4''*8''rectangle for each hole.