Novembergrl: I'll try to answer some of your questions. I have an 1100 gallon pond, deeper than yours but things should be similar except I'm in a lot colder zone than you.

I suggest you get yourself a skippy or some other similar upflow filter. I use a 600 gallon per hour submersible pump. The pump is in a large plastic flower pot weighted with pieces of half brick so it sinks and stays down. I have a loop of black nylon cord through a cork for a handle that I use a stick with a hook to move it in the pond. I have similar handles on all my plant pots. I use those laundry bags to protect delicates stuffed with nylon scrubbies as the prefilter. By putting some 1-2 inch stones in the bags with the scrubbies, you can arrange them so that you can stuff them tight around the pot so that they serve as the prefilter. My pond starts in mid April and is taken down early November. I have to clean the pre-filter about 4 times in that period.

When I first start the pond, I get the pea soup green algae bloom. My biofilter starts to work on it in about 2 weeks after which my water is clear. I get string algae but the cure for that is to have lots of other plants that are growing. I ensure they grow by giving them iron supplement which also contains some other trace nutrients they need. If the plants are growing properly, you should not have a big problem with string algae.

I do have goldfish and yes, I get visits from Mr. and Mrs. Great Blue Heron sometimes. I do lose some fish but the depth of the pond makes it hard for them to take more than 1 or 2 and then the fish are scared and stay deep. They reproduce fast so I have no need to buy more. I also have 10-20 rosy reds which you might consider having as they are more colorful than mosquito fish.

Activated carbon and charcoal are the same thing. A rule of thumb is hour pump should pump 50% to 200% of the volume of your pond per hour so a 600 gallon/hour for your pond should be good. You should be able to put a skippy behind your waterfall arranged so it feeds the waterfall.

14" is not very deep. You might consider digging the center of your pond down to 2' or so to give the fish more hiding places and also give your pump a deeper place to sit.

Thank you for the info, kalevi. I love the idea of the cord used as handles making things easy to move around. How do you get the cord to stay around your pots to move them, and can you lift them out of the pond with that? Your stick and hook must be really heavy duty; how did you make it?

I'm not completely sure what a skippy is. I googled it and came up with several Skippys Pond Pages, & Skippy Panut butter, among other things! LOL I think it is a home made biological filter, it that right? Is there a link you can give to show how to make one? (I also remember reading on the forums, a post by a lady who was willing to send you the plans for her version, but can't find it now.)

My waterfall has a hose that sticks out about 6 - 10 inches, to attach the tube to the pump. I think for a filter (skippy?) behind the waterfall, I would have to put the tubing from the pump to the skippy thing, then to the hose coming from the top of the waterfall. Does that sound right?

Do you put the scrubbies inside or outside of the pot containing the filter? I thought that box you make
containing the filter WAS a biological filter of sorts.

Do the rosy reds have another name? I think I looked for them once long ago, and couldn't find them here.

Besides the Herons, we have the big white Egrets mostly. The Blue herons are the worst. When one would come, I had a supply of pebbles to throw at him to scare him away. He would just fly up into a big tall pine tree in my yard and wait me out! They are not dummies! LOL

For the cord + cord: I use a 1/4" drill to put a small hole near the lip of the pot on opposite sides. Push the cord in from the inside and then put a knot in it (assuming the cord is a little thinner than 1/4" so the knot retains the cord).

As long as you keep the pot underwater, you don't need a very strong stick to drag it to the side so you can reach it. I use a 6' long 1x2 with a threaded hook screwed into the end. You might want to drill a pilot hole so you don't crack the wood.

Skippy Filter is a do it yourself bio filter. There are several ways to go using either a rubbermaid or a 45 gallon plastic barrel. For media, springflo, nylon scrubbies in dryer bags, ... can be used. Think twice about lava rocks. http://www.skippysstuff.com/biofiltr.htm puts you to the skippy site. You can buy one of their kits or you can do your own or a variant like these http://leisure.prior-it.co.uk/build-diy-pond-bio-filter.shtml or from this list (not all work and some want money) http://www.mikebentley.com/ponds/homemadefilters.htm
Mine is kind of like this http://www.blondieswebdesigns.com/water_garden/filter/index.html

Most ponds that have a waterfall driven from a upflow filter have the waterfall arranged so that the water flows out of the filter and falls onto the waterfall face at the top. I couldn't find any quick pictures.

The pot holding my submersible pump is 3 gallons or so, a bit broader and shorter than a standard plastic pail. I stuff the scrubbies which are inside the laundry/dryer bags on top of the pump so the pump has to draw through the scrubbies. These act as the prefilter. By scrubbies, I mean the colored little pads of nylon, not the green rectangles but they would probably serve.

Rosy Reds are a pink form of the fathead minnow. This is a good site to read up on them http://www.fishpondinfo.com/rosies.htm You can buy them as feeder fish in many pet shops for 10 cents a piece or so. They will breed in your pond.

Yes, the herons are smart. Mine wait on my neighbor's roof until I go back in the house. They are only a problem until my plants cover most of the water.