Quilt batting clogs really quickly. I only use a very coarse pre-filter to keep the big stuff out of my pump. My filter is a variation of the skippy filter. Very easy to clean, just open a valve at the bottom of the tank.

I have a 300 gallon stocktank watergarden. Sounds like our falls might be similar.
I have a 450 gph pump. I have a box filter that I put the pump in. It has the 2 pads of filter material. I only have to clean it about every month or so. The water isn't crystal clear, but its good enough.
I'm no expert with filters or pumps, that's for sure.
But here's a few thoughts I have.
Is your filter at the opposite end of the pond as your falls? How often do you clean that filter?
Is it possible that you're using too big a pump and it clogs the filter too quickly?
How about putting some oxygenators in your pond, like elodea?
Do you get lots of algae on your waterfall rocks? (what's your waterfalls made out of?).
Okay, that's enough questions for now. :)

P.S. I also have a couple 300 gallon above-ground stocktanks, with just lilies and marginals, and have no pump or filter, and they are crystal clear! Maybe you're trying too hard?

Hahahaaa! Maybe I AM trying too hard! Thanks for your responses, clarke and catherinet--I appreciate it. My filter surrounds my pump, which is at the same end of the pond as the falls (made out of rocks--the black rubber tubing from the pump to the rocks makes the waterfall). I did put an aerator at the other end a couple weeks ago--made for ponds, two small air stones and a little pump. Makes some good bubbles. My waterfall was going so slowly one day that the poor fish were sucking at the surface. I poured a half bottle of hydrogen peroxide in and pulled the pump and filter and cleaned it as quick as I could. That's when I bought the aerator. I will try the elodea as well. Poor fish.

I get string algae on the rocks. Sometimes a lot, I guess--I clean it off and it comes back. It doesn't ever completely cover the rocks. Who knows how much is down in the pond--have not seen the bottom for some time. The filter around the pump is the only one currently. I was thinking about a biofalls but I haven't seen one for a small pond like mine. If I wrap the pump in QB, and then maybe keep the box filter as a bio filter, not putting the pump in there, would that be sufficient? Would it slow the pump down to a crawl?

The water not being clear bugs me, but I am really concerned about the fish and the frog who lives there too. Thanks all.

-Jo

Hmmm.....that might be your problem. You're supposed to put your pump as far away from the falls as possible, so that it draws from the whole pond and cleans and aerates all the water. You might just be cleaning the water in a small little circle between your pump and falls.

Somehow, I never thought about that. I guess I figured it would all circulate eventually. I will get a longer tube today! Thanks catherinet.

Let us know if that helps nearzealot.
Do you have any pics of your pond you could share with us?
You might have to clean your filter several times in the next week or so, since it will probably be drawing more stuff out.
If I was wrong about it helping your water clarity, at least your fish will probably get more oxygen by putting the pump further away, since it will pull that great oxygenated water from the falls clear over to the other side.
Good luck and keep us posted!

Thanks Everyone!

I am finally done with gardening and off to get a longer hose for the pump. I will post a pic or two when I get back. I will keep you posted. And I will plan on cleaning my filter(s) a lot in the next few weeks!

-Jo

I use a similar filter for my 900 gallon pond only it is as a pre-filter to the pump rather than surrounding the pump. Works like a charm. We used to use a bucket with holes drilled in it filled with lava rock surrounding the pump but it was too heavy to lift out and clean. Scrubbies or similar are so much lighter.

Try leaving the string algae alone rather than scrubbing it. It often will clear your water. Trying to make a pond too clean will prolong algae blooms.

I do think having anacharis (similar to elodea) makes a big difference. At least I know it has for me.

Green water won't hurt your fish or frogs.

Well I spent a bunch of time getting fittings and hose and thinking about things and finally got time to put it all together tonight. And it didn't work. I got a longer hose, and the box that my pump goes in (with quilt batting and scrub-donuts and bio-balls) was pretty shot, so I thought I'd use the other shallow filter box and put everything in that, and take the cage off the pump to expose the fitting, put a hose on that, and attach it to the box. I don't know why but it didn't work at all. No water came through that box, and it doesn't make any sense. I took pictures and I will try to put them in the photo gallery. So I just put it all back together. I succeeded in putting the pump/filter box farther back from the falls, and that's about it. Very very frustrating. I will work on it again when I can, which probably won't be until at least Thursday. Thanks for your support and suggestions. Buyorsell888, I really thought this would work well. It sounded like your setup. Thanks for letting me know the green water won't hurt the fish or frogs. At least I know they're ok. Saw a new, tiny frog tonight. That was uplifting!

How's it going nearzealot? Hopefully things are coming together for you.