Bottom drain again

[Bdun111]

Hello again. I have a couple of more questions about the current pond setup my mother has.
1. In the pond picture I am attaching, I have only been able to locate (1) bottom "drain". The location of the drain is in the center around the 6 o'clock position, is set in concrete, has a round plastic grated top and when I first located it, there were 2-3" rocks surrounding and covering it. The whole pond bottom has these rocks.
My question is, would there typically be only (1), for roughly a 9x14' , 2-3k gallon pond?
2. The other question is about the horizontal submersible pump/skimmer photo attached (stock photo)

. When looking at the pond picture the pump is underwater in about the 1 o'clock position, with the intake facing the waterfall, about 5" from wall. The outlet pipe goes into wall around the same area, through filter system and returns as circulating water around the 8-9 o'clock position, and points right to the intake area of bottom drain.I'm guessing that is intended to keep debris away.
My question is, is this the correct position for the pump to create the suggested "Vortex" effect?
The pond is murky due to me stirring it up.

 

[Bdun111]

Thanks for everyone's help so far.

I have attached a "stock" photo that is similar to what we have in the middle bottom of our 3-tier pond waterfall. It is situated on a 2'x2' concrete riser. This bottom drain is part of our external pump filtration system, so water is pulled in from pump , then through pressurized UV filter, before returning as waterfall water.

My question is, should this drain be covered with rocks, which are covering entire pond floor bottom, or clear of all such items?
As previously posted, I have been trying to find out why bottom tier of pond isn't as clear as other areas.
I discovered that when I cleared away rocks, then all debris (small sticks, etc.), from the grate and riset, that the waterfall really started working.
Thanks for your help.

 

[mgmine]

One drain is enough, think of a huge swimming pool it would only have one. The drain should be covered with rocks it will cut off the circulation. I don't see any reason that it would matter which way the pump was facing. The water will pump in an direction that you put the pump.

 

[Bdun111]

Thank you for the reply. Maybe I ramble too much and give too much information. But, do you mean to say the drain SHOULD be covered with rocks?
Basically, I just need to know if the bottom "drain", which thru water is pumped through external filtration system and back in through waterfall, should be covered with the same rocks covering the pond floor, or should the area on top and around drain grate be clear?

 

[HARO]

As you noticed, the rocks covering the grate restrict water flow. Keep them a few inches away from the drain.
John

 

[Mucky_Waters]

Thank you for the reply. Maybe I ramble too much and give too much information. But, do you mean to say the drain SHOULD be covered with rocks?
Basically, I just need to know if the bottom "drain", which thru water is pumped through external filtration system and back in through waterfall, should be covered with the same rocks covering the pond floor, or should the area on top and around drain grate be clear?

Frankly, you would probably be better off with NO rocks on the pond floor.
But lets step back a bit. How many pumps are being utilized on this pond? From what I gather you have one external pump and one submersible pump? Is that correct?
About the bottom drain,,,,, it sounds like what you have is a pump intake located near the bottom of your pond, not what would commonly be referred to as a "bottom drain" in pond keeping terminology. The main difference is that a proper bottom drain should be gravity fed, meaning that the water from the pond gravity "drains" into another point whether it be a sieve, or a settling tank, or whatever, and the pump is located somewhere after that point. If the suction is created directly by the pump then it's basically just a pump intake located near the bottom of the pond.
Check this out,,, http://theponddigger.com/bottom-drain-technology/
It might seem like a small difference, but it makes a big difference in how it all works.

 

[Mucky_Waters]

BTW looks like a very nice pond setting.