Think about adding a UV light to kill the suspended alge (the stuff that makes the water look green). In all cases, make sure the filter(s) is/are correctly sized for your pond (too big is better than too small) and the water turn-over rate is sufficient. Ideally, the pump and filters should be able to filter all the water once every hour or, maybe, once every hour-and-a-half.

Take a look at the Franke Little Butler system, model DW-100 cost $200.00 - $250.00 comes with a small filtration system, Model LB-1000 which is instant hot water dispenser which would cost about $300.00 - $400.00 or LB-2000 which is Filtered water and Instant hot water dispensing out of the same spout cost $400.00 - $500.00 for a complete set. Filters last 6 to 12 months I guess depending on how often you use it and the quality of the water going into the filter, filter cost about $75.00 to replace. We have had great response so far, looks like the filtration system reduces Chlorine, Lead and other heavy Metals, bacteria, protozoan cysts, reduces sub-micron asbestos fibers also reduces foul taste and odors but leaves essential minerals intact. If there is a room issue you can even consider getting a faucet with a 3rd control knob which would dispense filtered water only when you need it this way you donÂt use up the filter each time you run water to wash dishes . You can view these items at kbauthority com for more information. Good luck! Should you have any questions please let me know  George Here is a link that might be useful: Franke water filtration

Regarding division of pump flow: actually, the division of flow really depends on resistance and back pressure. For example, I used a 20 gal small garbage can as a Skippy Filter and intended to split the flow 50:50 to that skippy and the rest to another portion of a stream. It turned out that the skippy lines were so resistant that 3/4 of flow went the other way and I had put a ball cock on the skippy line which didn't need any attenuation. If you wanted to control your splits, I think I would put ball cocks on all lines so that you could set controls as needed. However, I suspect you would be happier not fooling with bottom cleaning and let the stuff build up out of the way. You might want to google or just search here for cliffandjoann and filter to see if their detailed pump filter system would help. Their pond is much bigger, but I suspect that your filter system is too fine, too small, and will be a big pia and other than the skimmer, you might want to fill it with a media catching deal like sponges or something else like a skippy uses. Of course, I have never convinced myself of the usefulness of my Skippy. I have a big stream filled with plants and great gobs of plant roots that I believe do most if not all my filtering. The Skippy probably does do some biochemical activity, but at least many years ago now, I removed the skippy looking for a leak, and found it to be almost clean of any thing obvious. Now, the sponges etc all seem loaded to the gills with muddy stuff, so I suppose it is really doing something.

I just realized that I probably have an answer. I don't actually have real filtration at my in pond pump. It resides inside its own case with lots of slits, but that just keeps out fish and big crud. You probably have some fine sponge stuff or something that is too fine for a small area right at the pump inlet. You may not really need any filtering and to the extent you do, it should probably be a larger area of filtering. Perhaps you could make a small 'Skippy' filter (google it). They actually call them 'mini me' filters. It is a diy filter thing in a small garbage can. As I have mentioned many times, my filtering is mostly via my stream with plants whose roots catch everything. You could add a baby streamlet and probably do as well as a small Skippy. btw, I gather that your pond isn't very deep because it would then have a larger volume. Small volume means less filter need etc.