What's the best way, or product to use to clean and keep pond algae?

Barley Straw Bundle, available from Fish centre...

http://www.watergarden.org/Pond-Info/Control-Algae

API Pond Algaefix Algicide

By API and also put in a fountain pump that is solar it will keep the water circulating and oxegenate the water for the fish

Ask you aquarium expert - they can show you fish and other aquatic animals that can eat the algae and aquarium plants that will do the same and alter the water chemistry so the algae is reduced or gone completely.

UV lights lose their effectiveness over time. I've just installed a 3 tube flycatcher & they recommend replacing annually! I think I read somewhere that pond UVs also recommend the same.

That's a start.

Algae forms because there's too much nutrition (from detritus, food, poop etc) it really loves to 'eat' all that excess - so maybe divert the outflow from your filter (or even a solar powered pump?) into a small bog garden - a long tank full of plants that thrive on the same nutrients. I have a 4' trough clad in decking, the trough has a number of partitions where the water enters at one end then is forced under the first, up & over the second, under the third and so on, then out the other end into the pond. Each partition contains loads of plants in gravel which thrive on nitrogen & all the other nutrients.

A quick fix would also to be to swap out a good deal of the water & replace with whatever you have to hand - I just use tap water & my fish are fine.

Cute pond! I have a pond very similar to yours except I turned the upper (Waterfall pool) parts into bogs absolutely full of plants. I run a UV light and keep the water flowing 24/7. I tried the barley straw bundle with some results but not the clean water I was looking for.

My husband read an article that suggested I had too few fish in my pond. He bought me High Fin Banded Sharks (actually not sharks at all) and a bunch of koi.

The pond is clearing up!!!!