What is the best build to keep a salt water tank clean

So the setup someone gave me is where the water is feed from my main tank to a tank on the ground. Then through some green stuff ( I forget the name) the water will travel through 4 parts of the smaller tank. Then pumped back into the main tank. Which I dont think is a bad idea. But however I call a guy name Andrew Lake with Fish and Ship in Tyler. I seen a build he has being rented out and liked the setup. So what is the best and easiest long term setup for a 30 gal tank. I do however have a video here showing what I have going on as of now. Again I am open for change. I just dont want to break the bank on the hand. This is something I am in no rush to finish. I am going to be taking my time so that everything is just right when I get ready to add water and life into the tank.

You could save yourself the trouble and pick my tank up that I have for sale.. It's a 30 gal also.. Its a lot more safe to use a drilled tank than an over the top over flow imo.. I could really use it gone this week if you're interested

You could also turn this into a all in one system.
And have everything in one tank.

Can't put up a link from my phone.
I will once I get on the laptop.
Unless someone post up a link to matts 29g

Yeah that would be great. All in 1 for sure. I look forward to your reply.

http://www.etakc.com/t94-matt-s-29g-custom-led?highlight=matt+s

Sorry would have posted before.
But just got in from delivering a pup to someone.

Right now i have a aio setup in my 40 breeder. but isnt as thought out as this one.

Got it bro thanks I just sent him an email. U got photo's of your build?

I don't have any build photos.
I found a guy that build drop in ones online.
Kinda pricey but I wasn't good at using a router yet.
And still practicing lol.

I will look for the website on that guys stuff tonight when I get home