Pool Info: Low Pressure Pool Cleaners
Pressure-side pool cleaners are those that operate from water being pushed to the cleaner – under pressure, as opposed to suction cleaners, which operate from the suction of the pump. Pressure cleaners are inherently superior to suction cleaners, in that they capture debris in their own bag, and don’t draw it up into the skimmer basket or pump basket. They also don’t hinder the operation of a skimmer, whereas many suction cleaners are connected to the pool wall skimmer. They are helpful in distributing clean, filtered water around the pool. Even with the bag full, a pressure cleaner still operates, stirring debris up, it just won't suck up much more debris until the bag is emptied.
Lo Pressure pool cleaners such as the Polaris 360 or the Letro Legend II (now called the Kreepy Legend II) operate at a lower pressure (17 - 19 psi) than the Polaris 180, 280 or 380, which require pressure above 30 lbs to work effectively. This is why the 180/280/380 requires a booster pump to send higher pressure water to the unit. And of course, the booster pump requires hard-wired electric on its own circuit breaker, with its own timer clock as well as plumbing from the booster pump to the unit. The last few feet of the pipe can go under the pool deck and through the wall for best results, or the installer can use an over the deck mounting kit.
Booster pump driven cleaners do have 3 main advantages over the 360. One, since it has its own booster pump, the speed and efficiency of the cleaner is not dependent on the filter/pump system. That is, if your filter, pump or skimmers are clogged, the 360 will slow down from lack of flow. Secondly, the 380 usually is installed with its own time clock, so that it turns itself on & off. This will save wear & tear on the unit, and has a convenience advantage, making it truly automatic. Third, the booster pump models are faster because of the "boost" and (fourth) they also do not put any back pressure on the system, which will happen when you plug a low pressure cleaner into one of the return lines.
Lo Pressure cleaners do not require a booster pump, or plumbing or electricity. The installation requires only plugging it into one of your existing returns on the wall, making adjustments to reduce the flow from other returns to achieve 17 - 19 psi of water flow to the unit. NOTE: A filter pump of at least 1 hp is needed to achieve proper pressure. Small duty pumps such as the MaxFlo, the Maxim, the PowerFlo or other above-ground or small inground pool pumps do not have enough power. A pressure tester is included with the Polaris 360. It is advised that you properly pressure test the return port for proper water flow (pressure) before installing the cleaner into the pool.
The Polaris 360 comes with detailed instructions on how to connect it into your particular wall fitting. A G-9 wall adapter is needed if you are connecting it to a 3/4" threaded wall fitting. The Polaris 360 has 25 feet of feed hose included. If your wall returns are on one end of the pool, you may need additional hose sections for complete pool coverage. The Polaris 360 or Letro Legend II are suitable for vinyl-lined pools and for gunite pools of any shape. They also make the best replacement for the Jandy Ray Vac pool cleaner.
These cleaners attach to one of the existing return ports, or to a dedicated cleaner line. If you currently have a dedicated 'suction' pool cleaner line, it can be converted to a 'pressure' pool cleaner line.
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 internal back-up valve reverses the flow every few minutes to change its pattern and remove it from possible obstacles. And this is how it works!
Low Pressure pool cleaners work best on a dedicated plumbing line and specifically on a pipe that diverts water from before the filter, like the Jandy Ray-Vac plumbing set-up. They also need a pump and filter that can maintain decent pressure - otherwise, these cleaners can run very slowly.
Low pressure cleaners will never be as good as a booster pump driven, (high) pressure cleaner, but for many pools they operate very well, at a cost that can be 70% less than their more powerful predecessors. Just remember to shut off the cleaner after a few hours, if left running for long periods of time, it will wear out parts very rapidly.