You could wrap the pump with quilt batting and change it every couple of days, that will get some of the floating gunk out of your pond. I have a skimmer and a bio falls and I still wrap the pump up otherwise the stuff just floats thru the pump and down the falls with nothing to catch it unless its bigger stuff like leafs then the skimmer net catches that stuff.

If I was to choose only one item to go with of the three: skimmer, biofilter, UV filter, I would not have chosen UV. Biofilter is far more important. A UV just kills suspended algae and does nothing at all towards filtering the water for fish health.

You can add a biofilter fairly easily. Google Skippy Filter for a great DIY one.

Using quilt batting will help get some of the solids out of the pond.

i built a prefilter made of 2 small buckets. i put a nipple in the bottom side of one bucket that would fit a matching nipple that i placed on the intake side of the pump and a hose between the pump and that bucket. i took another bucket and drilled 4 2" holes in the bottom. i put a stone in the bottom of the bucket with the nipple in it to keep it on the bottom. i then placed the bucket with the holes in the bottom inside the other bucket. i made a pad of quilt batting to put in the bottom of the bucket with holes and then a small stone to keep it from floating out, then the whole rig goes into the pond. you will need to purge the air from the hose by filling the buckets then lifting them to allow water to fill the hose. i only use this on occasion and it works well to help clear up the water. you will be surprised how much gunk is in that quilt batting when you clean it. you may have to clean the batting frequently to start with. i actually have used mine as a sort of skimmer by adjusting the height to where it was a 1/2 to 3/4 inch under the water. i made to hose long enough to allow me to remove the filter to clean without disturbing the pump.

Hey Coastal ponder, I'm having trouble visualizing this. I'm about to re-do my plumbing so this would be a good time to make a new pre-filter. Do you have a picture of your set-up you could post? And how long do you generally have to use this one before you say that's enough? Few hours? Couple days? I find I'm more patient if I have an idea of how long I have to be patient. Otherwise, I tend to give up too soon!
Vanessa

magdaloonie, i'll try to get a photo or two and send them to you. is your email address up to date? might be a day or two though.

in answer to your questions, it depends on how bad the water is. when i first used it i had to clean the pad every 4 or 5 hours the first day then once a day etc etc.
it took me about an hour to build and the only real expense was the hose and some clamps, all of which i bought at lowes. i was having some severe problems with some scummy algae. between adding some potash and this filter it was cleaned up in a few days. the filter would collect the floating scum as it rose to the top. the potash allowed my plants grow better thus reducing future algae problems.

That sounds great especially for the spring when I have the worst problem with the floating scum. I'm going to try it. Pictures would help as I'm a pretty visual kind of person. My email should be up to date but I found that replies through Gardenweb have a habit of ending up in my spam folder. Use this email: magdalena.vanessa@yahoo.com. I won't be doing anything till next weekend anyway so don't rush but I do appreciate it and I'm sure others will, too.

Sorry for highjacking your post, Leslie! Maybe you'll build one, too! I have a homemade skippy that works pretty well despite my slow-growing plants but I did add a UV, too, just for the green water. It hasn't been doing so well but I just discovered that when I thought I had been calculating gallons per hour, I was actually calculating QUARTS per hour! Well, no wonder! If I had a bigger pond and could manage more plants earlier in the season (it gets cold here at night most of the year), I wouldn't have considered the UV but I think it might be good for my situation. Your situation sounds like debris and algae. Biological and some mechanical (like coastal ponders pre-filter) seem like a better bet to my in-experienced mind.

Vanessa

In answer to all of the above - I can't add anything to the present pump and tubing. The pump is submersed in three feet of water under several heavy rocks, and the tubing runs up and around under the waterfall. The guy who installed it was planning on "bleeding" me each Spring by removing the fish, emptying the pond, scrubbing it, refilling, etc. He told me to turn it off periodically to backwash it, which would clear the pre-filter.
The way this thing is put together, I either have to run a second pump, and figure out how to camouflage it, and its tubing, or wait till this pump dies, take everything apart, and put in a better system. I am not happy about even having someone try to maneuver the tubing - the waterfall might have to be taken apart, to some extent.

Today I climbed all over the waterfall, pulling off handfuls of string algae which was covered in brown muck. Most of the dirt washed down into the pond while I was working. I also added a load of extra rocks and pebbles in the three areas at the top of the waterfall which the water flows through before streaming down into the pond, hoping that some of the dirt would settle to the bottom up there, and the water would wash over the rocks, bringing down clearer water. For some reason, a lot of the rocks up there have either settled in, fallen in, leaving just open pools where the water just builds up, and then flows back into the pond.

I know there are pond clarifiers out there which supposedly bind particles together, and cause them to sink to the bottom. Any suggestions? Is there a type of mechanical filter I could set up with a separate pump on the edge of the pond, to use occasionally, for some period of time, to clear some of the debris out? I can't put a skimmer in without pulling up all the landscaping, and cutting an opening in the liner, which comes out fairly far from the pond itself. I was wondering if there was a type of filter which I could just put into place occasionally - the equivalent of using a large pond vac.

First, go to the attached link and read it over. It will explain why rocks in the bottom are a bad thing. You don't want the rocks to trap the gunk. It's still there, decaying and providing breeding grounds for harmful bacteria and parasites. The only way to have a healthy pond with rocks in the bottom is to do a complete clean out once a year, like your pond builder wanted to do. That's why he loaded rocks in there....so he could make money every year cleaning your pond. That decaying crud trapped in those rocks is very unhealthy for the creatures that live in the pond.

Cindy

Here is a link that might be useful: thread that explains things a bit