Right pressure filter for Sequence 7800prm24

[Erin]

Hi, I am a novice and inherited pond and pump with the house. So, I have a prefilter and a Sequence 7800 pump. I am looking to get a bio pressure pump with UV light.
Now my questions:
Is a bio pressure filter with uv a good choice?
My pond is half the day in the sun and mid summer all day.
As a result I have algae overgroth.
I would like to change to christal clear water and would like to keep costs as low as possible. What are my options?
Most pumps I see have a 4000gph max. My pump has 7800gph.
Also will a uv lamp kill all my good bacteria in the pond, prefilter (prefilter see picture)?
Looking at "Grech CPF Pond Bio Pressure Filter (CPF-20000)" but if I could get away with it would prefer "Light 10000L Koi Water" because of the better price. But I am not sure if my pump is too powerful. Please advise.

 

[Meyer Jordan]

regardless of what type of biofilter you use, it must be rated for a minimum 7800 gph flow rate. You have several options but none are inexpensive. BTW. that is a nice pump. A little pricey ($1,000+), but nice/