Double pond question

[Handyman]

Scenario:
2 ponds, each 2.1m dia x 0.8m deep.
There are fish in both ponds.
Pond #1 is 0.5m higher than pond #2.
Water is pumped from pond #2 to pond #1 and drains back into pond #2 over a 30cm wide waterfall. Flow is adjusted with a valve on the pump feed.
I now want to introduce a high efficiency filtration system.

Now, two questions:
Q1) If I pump the water from pond #2, through a filter system, and into pond #1 (on the opposite side to the waterfall outlet), will I end up with static water areas in pond #1, or will there be sufficient flow to stir up the water?

Q2) If the flow through the filter produces an acceptable flow over the waterfall, then that's great, but if I need to increase or reduce the flow over the waterfall, this may exceed the filter flow capacity, or reduce the flow such that filtration becomes inefficient. How can I maintain optimum flow through the filter, whilst being able to regulate the flow over the waterfall? Do I need a second pump?

 

[breezer]

.Now, two questions:
Q1) If I pump the water from pond #2, through a filter system, and into pond #1 (on the opposite side to the waterfall outlet), will I end up with static water areas in pond #1, or will there be sufficient flow to stir up the water?

It depends on where the pump is situated. it should be as far away from the returning water as possible

see here

.
Q2) If the flow through the filter produces an acceptable flow over the waterfall, then that's great, but if I need to increase or reduce the flow over the waterfall, this may exceed the filter flow capacity, or reduce the flow such that filtration becomes inefficient. How can I maintain optimum flow through the filter, whilst being able to regulate the flow over the waterfall? Do I need a second pump?

i would say that a second pump would be a good idea, that way one can run at "max" just for the waterfall, and the other can pump into the filter and return via the waterfall. but i suppose it depends on how much water your filter can filter