Pressure Side Cleaners: Inground Pools
These cleaners are those that attach to the pressure side (return) of your circulation system. The water that is being pumped or "pushed" back to the pool powers these units which have their own hydraulic power plant inside. Being on the pressure side, these units have distinct advantages. They are helpful in distributing clean, filtered water around the pool and having their own debris bag means that they don't compromise the filter system. Even with the bag full, a pressure cleaner still operates, stirring debris up. It just won't suck up any more debris until the bag is emptied.
These cleaners attach to one of the existing return ports and are powered by the pool pump (Polaris 360, Letro Legend II, Jandy Ray-Vac, etc.), or to a dedicated cleaner line and an additional Booster Pump (Polaris 380, Polaris 3900 and Letro Legend). For a complete list of swimming pool pressure cleaners, please visit our cleaners page. The water that flows into the unit splits into three directions; the sweeper tail, the thrust jet and the venturi.
The sweeper tail is a little stirrer-upper as I call it, which helps to get fine debris off the walls and floor and into the suspension where it can then head towards the filter. The thrust jet is a series of ports and gears which motor the unit around the pool in a random pattern. The venturi is the port where leaves are sucked up into a bag (that you empty when full) as the unit rolls over debris. An in-line back-up valve reverses the flow every few minutes to change its pattern and removes it from possible obstacles. And this is how it works.
The Polaris 180, 280, and 380 and the Letro Legend require a booster pump to power the unit. These cleaners need about 30 PSI to operate effectively, and most filter systems just don't run that high of pressure. The return pipe is cut after the filter and feed water is directed to the booster pump which then pumps water through a dedicated line midway down the pool wall. This line can be run under the deck and through the pool wall, or over the deck for a cheaper installation. Without the booster pump, these units would crawl along slowly, picking up very little debris.
Polaris 360 model operates at only 15 - 17 PSI, and thus is not intended for use with a booster pump. Letro followed suit and introduced the LEGEND II. These two cleaners I call "low pressure side cleaners." This has given these manufacturers a whole new market share by reducing the cost of installing one of their cleaners. The 360 & Letro operate in a very similar fashion to the booster pump cleaners and connects to one of the existing return ports. A test is made at that return port to determine if the circulation system can deliver the proper amount of pressure to operate the unit.
The 360 will not work well for pools with floor returns or "slit" returns of crushed copper pipe, or pools with small, slow circulation systems. The 360 and Legend II can be as effective in cleaning the pool as the booster pump driven models. The big advantage to the booster pump models is that they are usually run with a time clock, and can thusly turn itself on and off fully AUTOMATICALLY!