Joel Talks - Pool Service Q&A: Filtration

With over 22 year of industry experience, our Service Manager, Joel Fitzgerals, has seen alot!  This week, he's sharing information on Pool Filtration. 

Customer Question - "Which pool filter is best to use?"

Answer - When it comes to filters for your pool and spa, there are a few options but basically 3 main choices. Which one to choose? Well, let me define them for you. This list will not be a “best to worst” list as different environments are suited for different filters, but I will list them in order of micron size capture from least to most.

1. Sand filters:  Sand filters have the lowest filtration when it comes to particle sizes at 20-100 microns and most use a silica sand media. You might think “Why would anyone ever want a sand filter?” Well, ease of use would be the most prevalent reason. The sand bed typically is good for 2-8 years. This depends on having a good backwash regiment as well as minor environmental influences. The sand filter seems to be the filter of choice in commercial settings because of this. No need for bi-annual filter cleans or damaged cartridges/grids. The filters come with a backwash valve that allows the user to reverse the flow through the filter and flush out all the lovely things it has filtered out of the pool down a backwash line that goes either into the yard or into a drainage or sewer line. The backwash cycle is extremely important on a sand filter and should be done between 1 and 3 minutes. Now, as you can imagine, this will certainly drain a good amount of water from the pool, so it is very important to keep the level up when one would expect to perform a backwash cycle. If done improperly, you can actually negate the filtration by creating channels through the sand bed that would allow yucky things to go straight back to the pool! Areas that are prone to high winds and blowing sand are best for this filter as those conditions would be a bit too harsh for our other filter choices. The filter will show you that it is time to change the sand by clouding up the pool. Depending on the sand filter size, it can be a daunting task to perform a sand change, but innovations and synthetic products have made this a lot easier than in the past. Products like Ruby Sand can cut the media needed in half! Please remember, silica sand is considered hazardous material and should be disposed of properly. You definitely do not want to add it to the sand box!

1. Cartridge filters:  Cartridge filters are a step above sand filters in particle size filtration boasting a 10-20 micron size capture. Cartridge filters are by far the most popular filter choice as they are the best of both worlds. No need for backwash valves, the cartridges can handle most loads and are on a bi-annual cleaning recommendation. Most cartridge filters come in a 4 cartridge set-up and can be easily removed and cleaned by anyone that can watch a YouTube video. The lifespan of filter cartridges is typically 4-5 years but it is not uncommon to stretch that out more. With more frequent cleanings, doubling the life can be easily obtained. The gauge on top of the filter will keep you informed as to how they are doing, but there are certainly visual cues as well that are usually seen at the spa when the spillover slows down from what it usually is, or reduced flow in the pool in general.

1. Diatomaceous Earth filters: These are the kings when it comes to particle size filtration, boasting the ability to grab particles down to the 3-5 micron size. If you’ve ever turned your pool lights on at night and seen floating particles in the pool, this is the filter for you! This filter also comes with a backwash valve because it uses diatomaceous earth (DE) as the filter media. The DE coats the filter grid or cartridge and captures the particles as the water passes through and back to the pool. Backwashing flushes out the dirt ridden DE and you would then need to add DE back to the filter to replenish what was washed out. Done deal you say? Why would I choose any other filter if this is so great? Not so fast my friend! While DE filters are amazing at what they can do, they are also the most finicky of the 3. The DE powder is like talcum and when something goes wrong in the filter, you can turn a crystal clear pool into milky white in no time. Also, while you have the ability to backwash and extend the cleaning cycle of the filter, it still does need to be taken apart bi-annually to be completely cleaned. General maintenance can be harsh on the internals so be ready to dig into your wallet. Some municipalities and HOA’s do not allow DE filters so be sure to check with them before having one installed.

All in all, every type of filter available for your pool and spa will get the job done. Visiting with a pool professional about expectations and limitations will aid in a happy marriage of your filter choice and poolscape for years to come.

Do you have questions you'd like help with from Joel?  Give us a call at (281) 251-2577 and ask for him by name, OR send us an email at info@poolmaninc.com and let's see what we can do to help your pool ownership something fun instead of a high-maintenance worry!