Pond Boss Forums INTRO Questions & Observations DIY Pond Water Filter

One frequently given piece of advice is NOT to allow livestock access to your pond, as this can cause water quality problems and bank erosion. But if you fence livestock out of the pond, how can you let them drink water from it? The fence can be placed to allow access to a portion of the pond's shoreline, but this can still cause some water/erosion issues, even if your horses/cattle/etc. don't decide to go swimming past the fence.

I prefer total exclusion. Both of my ponds have 1" black plastic water lines buried through the dam (with anti-seep collars) to gravity feed water to a fenced off area below the dam for my cattle to drink. I believe it is desirable to filter the water entering the pipe to prevent fish or vegetation from clogging it. For the first pond, I purchased a filter assembly designed to obtain domestic drinking water from a pond (after proper treatment, although my cows get it as-is). This works fine, but 1) is designed for a pump-fed system, and therefore has a built-in check-valve which I had to by-pass to get it to gravity feed, and 2) is fairly expensive. I paid about $80 for mine several years ago, and they have gone up since then.

For the second pond, I built my own filter assembly from about $20 worth of parts and about 2 hours of my time. The raw materials required are 4' of 2" PVC pipe with an end cap and fittings to convert to 1" female thread, a 1" threaded-to-plastic pipe adapter (used), some fiberglass window screening (and I have a bunch of it left over to fix window screens with), and 2 radiator clamps (also used).


First, I drilled 6 rows of 1/4" holes into the pipe, over about 32" of length. This distance lets the holes be covered by the 36" wide window screening. I also drilled a pair of holes at each end, for the rope which will hold the filter to it's supporting float and it's stabilizing weight.


Next, I wrapped 3 thicknesses of window screening around the pipe, and secured it with electrical tape. I then glued the end cap on one end and a coupler and a 1" threaded reduction fitting on the other. The 1" threaded-to-plastic was screwed in to the reduction fitting.


Finally, a float made from a 1 gallon jug (Hint: If you use silicone bathtub seal on the cap threads before screwing the cap on hand tight, these NEVER leak. I have had one in my pond for over 3 years so far, including being frozen into ice cover, with no problems.) and a weight were tied on with nylon rope. The cleanest water in most ponds is 2' to 3' below the surface (below surface plants/algae and above bottom silt that may get stirred up), so the weight and float are intended to hold the filter assembly 2' to 3' below the surface.


When I can get a support crew for a half hour or so, I will attach this to the 1" water line through the dam, and be ready to water the cattle at the freeze-out hydrant below the pond next week when I change pasture.

Here is the hydrant, being installed about 20 months ago by Gallus, Jr.

Neato Theo, I love DIY.

Nice Theo. We did something similar about 30 years ago for irrigation from a lake. We used 2" galvanized pipe for a feed line, with a 90* fitting at the end. The fitting points up, and we drilled holes like you did, leaving the end open. We then slipped a piece of aluminum screen wire over that portion of the pipe, and used a wire tie at the 90* end. The first hole is about 10" off of the bottom of the lake. Nary a problem in 30+ years, although we do remove the aluminum screen every winter.