Breaking Down Your Pool Experience – Turn Chemistry and Mechanics into a Simple Routine
Today’s Edition: Filter Systems
A common mistake to make when talking about pools is not knowing the difference between the pump and the filter. The pump’s job is to circulate the water when the pool is not in use, and to create a constant flow of water pushing through the filter. It is the smaller, louder, motor-looking part that usually sits low to the ground, and has a strainer with a clear lid on it. The filter’s job is to sift your water through the filter media and remove obvious dirt and debris before being sent back into the pool through the return. It is the larger, round tank that is connected to the pump. The two parts together are known as the filter system.
A misconception about the filter system is that it will do all of the work necessary to keep your pool clean – this is not true! It is a reciprocal relationship; if you take care of your filter system, only then will it continue to work efficiently.
“But Eagle Pool and Spa – Home Relaxation Specialists, how ever do I maintain such a complex and burdensome system??”
Never fear! Like most forms of general upkeep, there are just a few main things to be aware of to uphold your end of the bargain with your filter system – filter media, filter pressure, and water chemistry. Let’s begin with the most common types of filter media.
The type of media used to clean the water is what defines a filter. There is not a whole lot to be said about cartridge filters. They are large, cylinder shaped filters made mostly of thick, pleated paper that will catch the dirt passing through it. While they are the simplest design of filter, they also provide the least effective filtration. Cartridge filters should mostly be reserved for smaller bodies of water – above ground pools with a largest dimension of 18 feet or less. Diatomaceous Earth or, more commonly, D.E. ($19.95/25lbs.) filters have an assembly of hard fins wrapped in cloth inside the filter tank. These fins require a few pounds of D.E. be applied to them through the skimmer to provide high-grade filtration. Sand filters are very much what they sound like, a tank full of fine grain sand that will hold on to dirt as water passes through it. While the filters themselves are easiest to operate, sand does not filter as finely as D.E. does. Finally, the crème de la crème, micromatic media. Micromatic media is a much thicker, porous version of standard pool sand that filters as finely as D.E., but is compatible with the simple functionality of the sand filter.
Filter pressure is directly related to filter media in that the pressure rises when the media is full of the captured debris. Filter pressure of about 20 psi or over weakens the output of the return – the pressurized stream that circulates your water. Circulation is the first step in filtration, making high filter pressure an issue of importance.
“Well then, pool care professionals, how is it that I get my filter pressure down to allow for optimum performance??”
The different methods of lowering filter pressure depend on the type of filter you have. For cartridge filters, take the cartridge out and soak it in a solution of ONE part muriatic (hydrochloric) acid to FIVE parts water for 12 hours. If you have access to a pressure washer, those can also be effective simply with some warm water.
D.E. filters, depending on how old they are, will either have a bump handle or backwash option which removes used, clogged, unwanted D.E. from the filter grids. The pressure should go down after executing those options, but it is of utmost importance to replace the D.E. you removed with new D.E. in the amount suggested on your filter tank. Should the pressure NOT go down, you will need to remove your grid assembly and soak them in the same acid solution previously recommended for cartridge filters. It’s a good idea to do this about once a year anyway.
Sand filters will have a multi-port valve on top of the filter tank with options labeled backwash and rinse. In this case, backwashing for one to two minutes will sift the cleaner media on the bottom of the tank upward, and rinsing for about a minute or less will re-compact the media to its proper filtering position. With traditional pool sand ($9.95/50lbs.), you will be able to do this for one to two years before reaching a saturation point, micromatic media ($32.95/50lbs.) will last at least five years before needing replacement.