Do I need bottom drains?

[Mucky_Waters]

have you ever tried NOT feeding them at all for a period of time? I bet if they get hungry enough, a lot of that algae will go missing...

I don't remember; does your pond have plants? I find a well planted pond also has less issues...

I have a well planted pond, between the lilies and the water hyacinth I generally obtain about 80% pond coverage in peak growing season.
I've never tried starving my fish but it would be physically impossible for my fish to consume the amount of algae I pull out of the pond and/or drain out of the settling chamber.

 

[Mucky_Waters]

Well, that could be the difference right there. The only algae we get anymore is the "carpet" variety algae on the rocks. We get several different forms of it, but no string algae in the pond - some on the waterfall occasionally, but nothing to write home about. Early on, we had LOTS of string algae that I would remove with a rake. It would form big clumps in the bottom of the pond that were easy to catch and rake out.

By "early on" I gather you mean early in the history of your pond if so that is interesting because early in the history of my pond I had much less string algae and more of the carpet variety. I guess every pond is different.

 

[sissy]

To stop collection of gunk on my bottom of the pond is by doing pipes with holes drilled in it that push extra water from my pump to it .I added my air plate from my aerator to it .Plus not feeding the fish every day really helps the clean their own house .I also have these in my waterfall pond .home made spitters.Can't find pics of the under water setup but it is similar and none of the pvc is glued and sump pump hose is just put on over pvc with 2 pipe clamps so I can pull t apart to clean the inside

 

[Lisak1]

early in the history of your pond

Yup - 1st two summers we fished out algae every day. Then once it was gone, it was gone for good.