Suggestions for a motor and a UV light for the bog filter of this pond?

[Jaguar.cic]

Can you all please tell me your ideas and improvements that can be added to this filter diagram?
A update of pond's work is also attached.
What do you think of Boyu and Sunsun brands in choosing a water pump for this? Boyu is the most popular brand in here to my knowledge.

 

[Jaguar.cic]

also tip for you having 50 fish you need to account for aeration add lots of air stones!!!

Thank you! Almost all of them are about 2 inches. Sorry that my previous reply wasn't really giving a clear idea about exact sizes.

 

[Jaguar.cic]

Update

 

[Jaguar.cic]

Update