Koi Pond Ideas- Need Review

[dr.weird]

Hey guys, I've been researching koi ponds a ton, and have finally begun my own. I'd like to give you a run down of what my plans are so far, so I can get some feedback from you.

So I've decided on a 7' x 5' x 4' deep pond. These dimensions come out to a pond of around 1000 gallons. I've purchased a 3" bottom drain, that will fun to my DIY vortex filter first, then to a Laguna PowerFlow 4500, then a Pondmaster PM 18 (1800gph rating) will pump externally about 2 feet max head to my homemade waterfall spillway.

I plan on adding a UV filter in the future, but don't have the money to worry about it yet.

I do have a couple questions:

First off, do I have these parts in the correct sequence?
I've read many opinions about what order they should go it.

So far my plans are: Bottom Drain -> DIY Vortex ->Filter ->pump -> waterfall.

Now the Vortex and the mechanical/bio Filter will be installed slightly underground to keep them on the same, or close to the same level as the pond to help reduce the distance the water must flow from the bottom drain to the filters. I've been lead to believe that gravity will be the worst to work help push the water from the bottom drain up to the level of my filters. Is this correct? This will allow me to not install the pump until after the filters and before the waterfall?

Second, is a pond skimmer neccessary in a pond this small (5'x7')?
I have not planned to install one so far, but I don't think it would be a huge amount of trouble if I decide to.

I've almost finished digging but still have a bit of expanding to do, before I put in the liner and install the bottom drain with the PVC tubing.

All questions/comments welcome!!

Thanks!

 

[dr.weird]

Let me add more detail.

The pond is REALLY 10'x6' right now. There is a 6" shelf on each side that goes down about 8" that I will use to place rocks on the sides to hide the liner. This makes the working width 5'.

On one side, there is a 1 foot area that slopes down gradually to a shelf 2 feet down (for plants), 1 foot farther this slopes down to the full 4'. This makes the length (at the bottom) about 7' The other sides of the pond however drop down the full 4' very steeply.

Now, I think I'm going to make another 2 foot shelf along the length of the pond, therefore the 2 foot shelf with go about halfway around the pond; around 2 sides.