Ever wondered if the sand in your sand filters for the pool is the same as sand in a sand play box for a child? Well the answer may surprise you. And is there a difference between an above-ground or an in- ground filtration system for a pool? These are all good questions and we will cover them here in this article. In addition, we will cover a few maintenance questions that arise from time to time as well.
Hopefully we can shed some light on this subject of sand and see if we can clear some things up for you.
A sand filter works similar to how Mother Nature does it on her own by filtering out water that percolates through the ground. Rather than allowing water to just percolate through the sand or ground to get clean like with Mother Nature, rather, water is forced through a cleaning system containing sand to accomplish the task.
The sand in a filtration system is not just any old sand that you can pick up at the sand pile; it is specifically designed to stop any particulates that are above a certain size. This is accomplished by the uniform granular size of a pool sand filtration system.
Normally the average size of the sand particles is between 45 millimeters and 55 millimeters. Studies have shown that with this uniform size the sand is able to collect debris as small as 20 microns. And anything over 100 microns will cause problems with a sand filtration device so there are larger screens generally found prior to the sand filter to keep them away from this portion of the system.
So if you have ever wondered where all of this collected material goes this is the reason that you, or a maintenance person, will have to back flush the system. This allows for the collected debris to be taken out of the sand filter and to clean out the system. Over time the sand, just like on a beach will wear down and become too fine to do its job and will have to be replaced. In addition, if there is a lot of debris in a pool, from leaves or a harsh environment, like a sand storm, oils, hair, the sand may not be able to clean itself properly after back flush and will have to be replaced.
Careful notes of water pressure should be kept indefinitely so it is possible to detect subtle changes over time. When the sand filtration device becomes clogged, pressure will increase. Then a backwash will be required. If upon completion of a backwash process the pressure does not return to normal, then replacement of the sand media will most likely be required.
Check with the manufacturer for the recommended pressure variables. And keep a simple log so that over time you will easily be able to see the changes that will come as the sediment becomes a problem in the system.
In addition the periodic backwashing helps the system to operate at maximum efficiency. If the system is half plugged up then the efficiency goes way down. This would be like driving around with the brakes on, mileage suffers greatly.
How long the sand will last in a filtration system largely depends upon the condition or the environment it operates in. As previously stated, if there is a lot of leaves or other debris that comes into contact with the pool this will certainly shorten the life and the same with oils and sun screens that are used. And one other item is hair. Hair from people, as well as from pets if allowed to be in the water will be collected in a sand filtrations system.
There are other options for filtering water for a pool; one is the use of diatomaceous earth or sometimes referred to as DE in the pool business, requires manual cleaning. The other is an alternative media such as paper or twine style media filters that need to be replaced when they become clogged with debris. This is not as simple of a process as back flushing a sand filter, and in the case of a media filter, there is the required purchase of a new set of filters each time the filters become blocked and cannot operate efficiently any longer.
In light of these options the expense of a $300.00 to $700.00 sand filtrations system is not a very expensive proposition. The life of the average sand inside of a sand filtration system for a pool is thought to be seven years. sand delivery in Flint, MI. sand delivery in Flint, MI. This depends largely upon the environment the pools are operated in and there are reports of systems lasting 20 years. Light traffic and not much foliage being allowed into the pool due to pool covers etc.
If you keep a simple log book you will notice when the sand is becoming clogged up and a backwash is not working as well as it once did. More frequent backwashing is required and you will see a steady rise in operating pressures.
Keeping the ph balanced as well as the overall water quality that is introduced to a pool will make an impact upon performance of a sand filtration system as well. Hard water will cause a build up in the sand as well versus soft water.
A couple of possible solutions is employing the use of a "green sand" system and or a water softening filtration system to reduce the high mineral content of the water entering the pool.
As with all equipment, following the manufacturer's directions will improve the life and performance of a filtrations system.
There are a good number of good cost effective sand filters for a pool including the Pentair, Hayward, Swim Time, GAME, Sears and the Intex brands. All have features that are unique in some ways but very similar in most ways to each other. The systems with a larger capacity will last longer than those of a smaller capacity as far as the sand media goes.