DIY Sump for 150L

[HygienicMermaid]

Hi all,

I am planning on upgrading my saltwater aquarium to a 150L here in August. I am looking at creating a undertank sump system, as I have a spare 20L that is just sitting around. What all would I need to start the system? Links to everything, please?

I have about $400 available for use on the system, so it'll need to be on the cheaper end. I tried looking things up, but got those classic "DIY" videos that utilized dollar store garbage.

Suggestions??
(NOTE: Looked on Bulk Reef Supply but was totally overwhelmed by all of the supplies. Have no idea where to even start.)

 

[TexanCanuck]

Check out Joey's posts on his "King of DIY" channel.

https://www.youtube.com/channel/UCM9oZkV3tGJuUUhgZaiGZkQ
While he posts a lot of stuff for freshwater, his stuff on sumps is equally applicable to saltwater.

Try these two in particular: