DIY Bead Filter

[Birdman]

Garrett Klein, a friend of mine from CA. has been working on a design for a low pressure bead filter, that could be built from a 55 gal barrel. Most bead filters create quite a bit of back pressure, 15 PSI and more, more than a poly barrel wants to handle, and then even more when running the blower for back flushing. Garrett's design for lowering back pressure is based on two key elements. 4" well screen pipe for the inlet and outlet and a vent when running the blower. Opening the vent when back blushing with the blower allows better air flow with out creating any additional back pressure. The 4" well screen pipe is available from AES and has .040 inch slots in it. These slots are small enough to not pass the beads, but with roughly two feet of inlet pipe and 2 feet of outlet pipe will pass plenty of water with out creating a lot of back pressure.
A couple of people on other forums have built these bead filters from the 55 gal poly barrels and are running them with less than 2 PSI back pressure, and they are working great. They hardly restrict any flow and are working great at trapping dirt and fines.

[Birdman]

Here is a drawing based on Garrett's design. Pretty simple to make with a 55 gal poly barrel, bulkhead fittings, and uniseals. Standard stuff for DIYers.
This filter is not actually "Back Flushed" per say, the flow is not reversed. When flushing you don't stop the flow, you just open the valve to waste, close the valve to the pond, open the vent valve, and turn on the blower. On mine I am using a short length of clear PVC so I can see when I am getting clear water out. The air from the blower will stir up the beads, dislodge all the dirt, and flow it to waste. Pretty nasty stuff comes out.

[Birdman]

One of the biggest problems we had was finding a good sourse for high quality beads. Most of the so called beads available are nothing more than "Pellets" used in the injection molding industry. They are cheap, they float, but are not very uniform in size and with a lot of defects will get trapped in the 40 thousands slots in the well screen pipe. So several of us on other forums went on a search for good cheap beads. You want beads that float, they need to fill the top half of the barrel, about 4 or 5 cubic feet for a 55 gal barrel.
We explored all sorts of stuff, got all sorts of samples, injection molding pellets, poly BBs, and poly doll stuffing. pellets were do crapy, BBs to expensive, but the poly bead doll stuffing worked out to be the best. It was the most uniform in size, with the least amount of rejects, and ordering it online in big bags, was the cheapest tp buy.

[Birdman]

For my DIY Bead Filter instead of using a 55 gal poly barrel I used one of the free fiberglass pressure tanks I got from the pump store.
Using the 3 foot high by 2 foot wide fiberglass Tank I had I 1st drilled a 5" hole in the bottom right for the inlet and a 5" hole in the top left for the outlet. These holes will accomidat the 4" uniseals for the 4" inlet and outlet piping. The air from my 2 HP blower will come in the bottom. I am using a 2" bulkhead fitting with a screen. My tank does not have a lid so everything I do has to be done in the right order, through the 5" holes. Last picture is the 2" bulkhead and screen in the bottom for the blower inlet.

[Birdman]

The vent coming out the top has to have a screen to prevent the beads from coming out when you open the vent. I used a short piece of the 4" well screen pipe for this. With a male adapter on the top and a cap on the bottom. Last picture is looking through the top 5" hole at the well screen pipe installed.

[Birdman]

The next thing I did was make the two 4" well screen pipes for the water in and out. I ordered my 4" well screen pipe from AES. I cut them to the correct length, glued a shortened cap on one end and a shortened coupling on the other. I then made a short piece of 4" pipe belved on one end to put through the uniseal. I put the inlet well screen pipe in the bead filter through the 5" hole and inserted the 4" pipe through the uniseal and into the coupling on the well screen pipe inside the bead filter.

[Birdman]

Once I had the inlet well screen pipe installed I made my base and installed the filter, and plumbed my pump up to it. 1st and 2nd pictures. Also when plumbing the blower I put a "T" in the 2" line so I have a drain from the bottom to waste. You can see the knife valve for that, I haven't finished plumbing it to the main drain line yet, to darn cold.

Next picture shows the 2 HP blower installed. I don't remenber where I got it, Bill from Roseburg, OR. sent me the link but it was only $120 or so. I put a 2" spring check in the line to keep water from backing into the blower.

The last picture is the alum. tray I used to fill the filter with the beads. Rich Little in CA. sent me 7 cubic feet of beads to use. Just the right amount to fill the filter half full.

[Birdman]

Here are a couple of pictures of the outlet well screen installed. I filled the filter with water so the beads would float just high enough to hold the well screen pipe in alignment with the hole. Then I installed the short 4" pipe through the uniseal and into the well screen coupling.

[Birdman]

Hows this for a plumbing mess. This is the outlet manifold from the bead filter. The top 3" line will go up to the vent, the bottom 3" line with the clear pvc goes to waste. The 3" line going left goes to the discharge manifold. This manifold will have three 2" single union ball valves to control flow through the three 2" lines going to the pond. The 1st and 2nd lines will each go through a 40 watt UV. The 3rd line will be stubbed in for a possible future heat exchanger if I ever install a heating system. The 3/4 ball valve at the end will go to my yard sprinkler system. Can't do any more until my stuff on order gets here.

[Birdman]

Got some more piping done today on the outlet and both drains. Next I'm going to run a temp. line back to the vortex so I can circulate water for a few days to check for leaks.