Help for a new guy....what are this second and third boxes for?

[spur0701]

Also....do I have to "Seed" this biofilter with anything or will the bacteria from the surrounding air take care of that?

 

[Meyer Jordan]

Found this youtube video:

So from it my understanding is I install a filter mat, the bioballs on top, with some more bioballs in a mesh bag and replace the dead pump and I should be good to go? Am I missing anything? How do I size the replacement pump? The outlet on the dead pump is 1 1/2" but there is no model number or anything else, just a notice that it needs to be placed 3" above the floor of the pond.

The filter will seed itself.
Measure the weir (spillway) width on the biofalls unit. Go to this web page: http://www.aquascapeinc.com/products/biofalls-filter#p-tab_224
This will give you the Maximum flow rate for your biofalls. The minimum flow rate should be calculated at 100 gph per inch of weir width for a minimal waterfall.

 

[spur0701]

So it's a 15" spillway, which looks like its the older version of the Microfalls and I would need a 1500-200 GPH pump.....any recommendations for any particular brand or just what gets the best reviews off Amazon?

 

[Meyer Jordan]

So it's a 15" spillway, which looks like its the older version of the Microfalls and I would need a 1500-200 GPH pump.....any recommendations for any particular brand or just what gets the best reviews off Amazon?

!500gph - 3000 gph would be ideal for this biofalls unit. I would tend towards the higher gph.
Any reputable brand of pump would serve your purpose. Many people look at only purchase price or electrical efficiency or warranty. All are important. I have always been partial.to direct drive for submersibles, but that's me.