Multi-Vent Underliner System is a patented, innovative and cost effective system designed to protect pond and lagoon liners from damage caused by methane gas and water accumulation.

Multi-Vent is a series of perforated tubes that install under the liner. The tubes are wrapped in a non-woven geo-textile to prevent plugging. By simply laying a strip of Multi-Vent on the ground before installing the liner you can prevent costly future problems. This easy to install system is effective, low cost and best of all does not require cutting the liner.

It takes a great deal of pressure for the water or air to lift the liner. With Multi-Vent, neither water nor air can build up pressure under the liner. Instead it will vent through tubes to the outside of the pond, eliminating any chance of the liner floating. Because of its low cost, Multi-Vent is cheap insurance under any liner job.

Customer Question:

My pond liner lifts every time the water table rises. Is there a valve that would allow the water in but not out of the pond?

Easy Pro Answer:

With a liner that is already installed it is not an easy fix unfortunately. If you can drain the pond and get under the liner we have our LAV - Liner Air Vents. Basically a bulkhead fitting with a pressure valve is inserted into the liner at the lowest point. When the pressure builds up under the liner this valve is popped open and the air or water is released into the pond. After the pressure is relieved the valve closes again.

The other option is to install the Multi-Vent under the liner. The liner would have to be removed to do that. The pressure of the water in the pond forces any build up of air or water up the Multi-vent and out from under the liner. Unfortunately, this is only sold in 125' long rolls and has a minimum quantity of two rolls. It also ships factory direct via motor freight. A little much for a small water garden!

Attached is the page in our catalog showing these items. Please note the manufacturer of the Multi-Vent recently changed the roll length to 125', not the 150' listed in the catalog. That change was made after the catalog was printed.

• MV6125 - Multi-Vent 125' Roll- Minimum order 2
• MV6C - Multi-Vent coupling
• MV6E - Multi-Vent end cap
• MV6Y - Multi-Vent "Y"
• MV6EO - Multi-Vent end outlet to 3" pipe