There are many pool and spa pumps to choose from and most are of similar quality. When installing a new pool pump it is imperative the size of the pump suits the filter. A pump that is too small for the filter will not push the correct amount of water through the filter, which will in turn effect the filter from working to the capacity in which it was designed. If the pump is too big the water flow rate will put a strain on the filter causing it to run at a very high pressure which can blow seals and valves and malfunction the filtration system. With ever rising electricity costs, pool pump manufacturers have been forced to design multi-speed pumps to stay competitive. These pumps do work well, but will require additional monitoring than a regular pump. They start off on the top speed and after a short period of time automatically wind down to the lowest speed, using less electricity. However, these pumps are a little bit of false marketing, as when the pump runs on the lower speeds it pushes less water through the filter. This means that you will often have to run the pump for longer periods than you would with a regular pump, which means false economy to the home owner. Multi speed pumps will not work adequately if a booster pump cleaner such as a Jetvac or Polaris is used in the pool. If you do have this issue, the pump will need to operate on the top speed whilst the cleaner is functioning. The pump can go back to the lower running speeds once pool cleaner has been disabled. FILTERS For any swimming pool to work it must have adequate filtration. A filter is needed to remove unwanted matter from the pools water. The filtration system works in conjunction with the pool water sanitiser (generally chlorine) to keep the pool water clean and safe for swimming. The 3 main styles of swimming pool filters are:
FILTER TYPE RATING
This means that D.E. Filters filter finer than sand filters and cartidge filters Each of these pool filters offer particular advantages when used correctly. One of the differences between the filters concerns the size of the smallest particle which each filter can remove. This ability to filter very fine particles is measured in micros (a micron is one millionth of a metre). SAND FILTERS The sand filter is undoubtedly the most popular swimming pool filter on the market. They come in many different shapes & sizes, manufactured by a wide range of manufacturers, regardless they all use the same mode of operation with the water forced down through the sand bed and the clean water is collected at the bottom of the filter. The sand is held in place by a series of “laterals” at the base of the filter. Sand filters use either “Silca” sand that has been strained to give a uniform size, or a glass medium which is a relatively new innovation. As water is passed through the filter, the sharp edges of the sand trap the dirt particles from the pool water. When the pressure raises due to a build up of dirt in the filter, the filter needs to be cleaned by “backwashing”. This is done simply by reversing the water flow through the sand bed so the dirt particles are dislodged and is pumped down the backwash (or waste) line. Once the sand bed has been backwashed for approximately 2 to 3 minutes (or the water is the sight glass is clean) then the sand is “rinsed”. The method I use to determine when a sand filter is clean is a little different to that of most pool guys, when the water going down the waste line is clear, the filter is clean. The rinse cycle on the filter will direct water down through the sand and down the backwash line. This process compacts the sand and causes any remaining dirt to be flushed down the drain rather than back to the pool. Once the rinse cycle is complete (usually 30 to 60 seconds) the multi-port valve (MPV) can be set back to “Filter” where the water is filtered then pumped back into the pool. CARTRIDGE FILTERS Cartridge filters provide the simplest form of filtration. The pool water is simply passed through a very fine but durable material. To clean the filter cartridge you need to remove it from the filter tank and hose it down to shift the dirt. Occasionally (generally 6 months) the cartridge will need to be soaked overnight in a cartridge cleaning solution (acid based) and then hosed clean and returned to the filter body. Although cartridge filters are not generally able to remove fine debris as a DE filter system, they do have some definite advantages. Sand & DE filters are cleaned by a semi-automatic cleaning process called “backwashing”. This process requires a sewer drain and a backwash line to take the dirty water from the filter to the drain (which on some sites, is not possible). Backwashing a filter also requires substantial volumes of pool water being pumped down the drain, which can be a problem with small pools and spas, or in drought stricken areas. Sometimes a Cartridge Filter is not housed in its own filter tank but instead in the skimmer box, under the simmer basket. This style of filtration operates in the same way as a normal cartridge filter except the water, instead of being pushed through the Cartridge Filter by the pump, is sucked through. D.E. FILTERS The water clarity provided by a Diatomaceous Earth filter is second to none. D.E. Filters filter out more microns than Sand and Cartridge Filters, but at a price. In a D.E. Filter there is filter material (usually made from dacron and nylon) which by itself can only filter out the large particles. However, when the filter cloth is coated with the fine power called D.E., the powder does the job of filtering the water to a very fine clarity. This powder is the filter “media” in a D.E. filter, as sand is the media in sand filters.When the filter is backwashed the water is passed back through the cloth in the reverse direction and it takes with it the D.E. and the accumulated dirt & deposits this waste water down the backwash line to the drain. This means that all we have left is filter cloth and not “filter media” so we must recoat the cloth with D.E. powder before it can operate as a filter again. D.E. filter cloth comes in many shapes and styles according to the skeletal shape that the manufacturers want to wrap the cloth around. The filter internals are called septums or pads. Because the filter cloth is required to hold the D.E. which is so fine, it is important that it has no holes to allow the D.E. to pass. If the D.E. escapes this white powder can return to the pool, making it cloudy until the torn septum is either repaired or replaced. To recoat the septum we mix the required amount of D.E. with water in a bucket, turn the pump on then with the filter (set on the “filter” setting) and then slowly pour the slurry into the skimmer box of the pool. The pump will carry the slurry through the filter and spread it evenly to a thickness of a few millimetres. Now the filter is ready for use. Never run a D.E. filter without D.E. in it. Always calculate the correct amount of D.E. to be added depending on the amount of cloth in the filter (measured in square foot). Add 350 grams of D.E. powder per 5 square foot of filter area. Please also note that D.E. accumulates even with regular backwashing. This means D.E.filters need to be dismantled and hosed out on site every 6 months and will also require an annual overnight acid bath to ensure correct operation. WHEN TO CLEAN The cleaning time for most filters is determined by a pressure gauge. As the filter becomes dirtier it becomes more difficult for the pump to force water through it. This will be shown by a rise in pressure. As a general rule cleaning is required when the pressure is 20 to 30 kpm higher then the original clean start up pressure. If the filter doesn’t have a pressure gauge a slowing of the water flow from the pools “return” line will signify that the filter is dirty. If cleaning is required D.E. and Sand Filters will need backwashing and Cartridge Filters will need hosing down. MULTI-PORT VALVE SETTINGS Sand Filters and D.E. Filters come with multi-port valve with various settings. There are six settings on the valve these include filter, backwash, rinse, waste, recirculate and closed. Filter– setting allows the water from the pool to pass through the filter in the normal direction and then back to the pool. Backwash– setting pushes the water through the filter but in reverse and deposits the dirt (and D.E.) down the drain. The filter may have a sight glass (a glass bulb attached to the valve) which when the pool is running normal appears to do nothing but when backwashing, vacuuming to waste, or rinsing has various colours of water ranging from clear to black passing through it. This sight glass shows you how much dirt is being removed from you filter while you are watching. When you see the water coming clear you will know the filter is clean and you can move on to the next stage of the cleaning cycle, rinsing. Rinse– setting allows the water to pass through the filter in the normal direction but it dumps it down the drain. This cleans the sand in sand filters and valves and pipework in all other filters. Use this setting after backwashing and before going back to the filter cycle to minimise the amount of unsettled dirt that returns to the pool. Closed– setting means that however much the pump tries, no water is allowed to flow through the multi-port valve. never start the pump in this position and be sure the time clock is off so it doesn’t start it for you. Close the valve for service reasons only and always remember to open it as soon as you finish. Recirculate– settings allows the water to flow from the pool to the multi-port valve and back to the pool without passing through the filter. This setting is useful for distributing chemicals that you don’t want passing through the filter (i.e. floc). Waste – setting takes the water from the pool and then down the backwash (or waste) line to the drain. This is a particularly useful function if the floor of the pool becomes extremely dirty. On waste you can by pass the filter, vacuum mud/dirt directly down the drain without clogging the filter. Don’t forget that a lot of water will go with the dirt down the drain so after the worst dirt is vacuumed to waste, change back to the filter setting to tidy up. Please note: Waste, Rinse and backwash all dump water as fast as the pump will pump. Your attention is required at all times when using these settings. Whenever you are changing valve settings, always shut off the water supply (the pump) to avoid breaking pipes, valves, etc. Never attempt to turn a multi-port valve whilst the pump and filter are running. Some older style rotary backwash valves have only 4 settings, Filter, Backwash, By Pass, and Aux Filter.The filter and backwash settings are the same as on a multi-port valve. By Pass is the same as the “waste” setting and Aux Filter is the same as the “re-circulate” setting. PIPE NAMES THE SUCTION LINE Connects the skimmer box to the pumps inlet. For a pump to work efficiently, the suction line must be completely free of any air. THE RETURN LINE Sends the clean filtered water back to the pool. The return line can also feed water to booster pumps for propelling automatic pool cleaners and sending water through solar heating systems, spa jets, etc. Most chlorinators are generally installed on the pools return line. THE WASTE LINE Sends water from the pool to the drain. This is used when backwashing or lowering the pools water level etc. Please Note: The position and number of skimmer boxes and the pool returns varies depending on the pools shape and size
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