Using the Silt Vac

The following instructions describe how you get the Silt Vac ready for vacuuming and how it's used.

Attaching the Leaf Trap

The mesh basket goes inside the leaf trap body. Make sure the closed end of the basket is toward the pump. I've put the basket in the wrong way many times even when we remembered to double check. So triple check.

The leaf trap body has 2 small silver posts on one end. The posts are lined up with the notches in the pump cap and the body is pushed into the cap and then twisted to lock the body in place.

Warning: The notch on the cap has a little tab that can break off. This is a known weak point in the Silt Vac. If one tab breaks off the vac can still be used. If both tabs break off the notch can be extended with a saw or soldering iron to create another tab. Or you can contact us for getting a replacement cap.

Placing Pump In Pond

The pump with the leaf trap must be inside the pond. It can rest on the bottom or be tied to something so it hangs from the side. In either case tying a rope or chain to the pump handle give you something to pick the pump up with and it can be secured to something so the pump can't drag the power cord into the water.

Plugging in the Pump

When plugged in the pump will start. Plugging and unplugging the pump to turn it on and off can be dangerous if you are wet. Read and follow all the safty instructions that came with your pump.

There are some ways to make turning the pump on and off easier and safer.


Wireless remote control. Plugs into outlet, pump plugs into device. A remove control switch will turn the pump on and off from 50 ft away. We paid about $7 for the device we use at Home Depot in 2001. Alittle tough to find but well worth it.

We keep the remove inside a pocket and press the button thru the cloth to keep the remote dry. If you have a helper they can control the button. When not in use we keep it inside a plastic container for safe keeping.

Heath/Zenith Model SL-6139-B

2.   Power strip or outlet with switch rated for outdoor use.

3.   Have a helper with dry hands pull and push in the plug. Make sure they follow all safty instructions that came with the pump.

Attaching Suction Hose

The suction hose must be attached to the leaf trap and vac head underwater after all air has been removed from the hose.

Steps for removing air:
  1. Make sure the pump and leaf trap is below water and air is out.
  2. Attach one end of the hose to the vacuum head.
  3. Place the vacuum head in the pond so it is underwater.
  4. Starting at the vacuum head force the remaining hose down into the water making sure the other end is near the surface so air can escape.
  5. When you get to the other end of the hose attached it while still underwater to the fitting on the leaf trap which is also still underwater.
  6. Because the hose is clear you'll be able to see any air trapped inside.

Turn on the pump to start vacuuming. If there's air in the system when the pump is turned on the pump will work but not create any suction. You can tell when there's suction because the hose will kind of jump and water will come out the discharge hose.


Always keep the pump, leaf trap, hose ends and vacuum head underwater while vacuuming or air may be drawn into the system and the pump will lose all suction.

You're vacuuming!

Vacuuming Tips

  1. The clear hose will show you what you're vacuuming.
    Clear  - Not over muck, time to move.
    Dark blobs  - Chunks of string algae, no silt.
    Gray  - Silt.
    Very dark  - Heavy silt, stay in that spot until lighter gray. Move slowly in that area

  2. Hose compresses - there's a clog in the vacuum head.

  3. Less vacuum after several minutes - leaf trap is probably full or there's a clog at the pump's intake.

Clogs and having to empty the leaf trap more than you like means this large debris should have been removed from the pond before vacuuming silt. The Muck Mop is much better at removing large amounts of large debris.

Cleaning the Leaf Trap

Lift the vacuum head out of the water while the pump is still on so air is drawn in. You'll see the clear hose fill with air. When air starts drawing into the leaf trap turn off the pump. Pull the pump and leaf trap out of the pond.

Never lift the pump by the power cord. The cord will not last very long if you do. Tying a rope around the pump's handle will give you something to use for lifting the pump. Plus the rope can be used to secure pump from going too deep into the pond.

Pull off the clear hose from the leaf trap. Water and some debris may rush out of the leaf trap so be ready.

Using the hose fitting as a handle twist the leaf trap body to unlock the posts from their notches. This may be a bit difficult. The pump's suction can draw grit into the joint between the leaf trap body and the cap. A little wiggling should get it lose. Don't use too much force, it's just plastic.

Pull the leaf trap away from the pump and the basket out of the leaf trap body. If you have alot of string algae the basket may look like the picture. The best way we've found to clean the basket is with a garden hose.

Check the grate covering on the pump and remove any debris. If you see debris inside the pump it can normally be removed thru the grate using needle nose piler or tweezers. If debris still can't be removed the screws will have to be removed. In about 3 years of vacuuming we've have never needed to remove the pump cover to clear debris.

Water loss from vacuuming.

Since water is pumped out of the pond expect about a 10% loss in a typical 3' deep pond. The more shallow the pond the higher percentage of loss.

The waste water can be reclaimed and put back into the after sitting in a holding tank for 24 hours. The silt will settle to the bottom of the holding tank and the top 90% of water can be pumped back into the pond. But this requires a fairly large holding tank, about 10% of the pond's total volume. Most ponders will prefer to pump the waste water into the garden and replace the water loss in the pond. This also does a 10% water change which many ponder routinely perform anyway.

Remove large matter first.

If your pond has a large amount of leaves, dead string algae, pine needles, pine cones, twigs, etc.. the Leaf Trap may fill up faster than you like. Ponds with these conditions should be vacuumed first with a Muck Mop. This will make vacuuming silt go much smoother and faster which means less water loss.

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