Sand Filters — Some things to watch for in your swimming pool


Have you noticed that your pool just doesn’t seem as clear and sparkly this year? Know that your pool is completely balanced. Chlorine is good. no algae, just not as clear as previous years.

There could be a few reasons this is occurring. Troubleshooting a sand filter problem is a lot more difficult than a cartridge filter or a DE filter. Usually to complete diagnose a sand filter, you have to do a lot of scooping and there may be a lot of scratches on the forearms. There isn’t a lot of room to move around in a sand filter.

Here are a few tips to help diagnose your problem:

1) When was the last time you changed your sand?

A sand change should be done every 3-5 years. The reason for this is that your sand has jagged edges, these jagged edges become rounded over the years of tumbling around and cleaning and backwashing. A filter can not do the same accurate job. Sand changes are usually best to be done at the start of the season when your sand is dry. Backwashing to often is often the reason sand wears out to soon, and your pool is having a hard time clearing. Backwashing should be done only when your pressure is 8-10psi over its normal PSI pressure.

2) Is there sand in the bottom of your pool below the jets?

Sand in the bottom of your pool.  This is usually a good indication that a lateral  has  cracked or the stem may have a break in it. Both of these  items are located inside the filter under the sand. In order  to  completely diagnose this problem you have to take the  filter  apart and inspect it. In order to take the filter apart, you  will  need to shut down the pool and remove the filter head and  scoop out the sand, or if you have a heavy duty shop vac will  also work. Once all the sand has been removed, you can  inspect the insides of your filter.

3) Is there hardly any pressure? Any leaks around the backwash line?

Do you have no pressure even after you have backwashed the full 3 minutes and rinsed for 30 seconds? Maybe you have noticed water coming from your backwash hose. These are good indications that your multi port valve needs replacing. Some filters have a gasket that can be changed but most popular brands require a new valve ( Filter Head). These can get worn out over time, or if not winterized correctly

Not closing your pool correctly is the reason for a lot of damages in the filter media and multi-port valve. One mistake a lot of folks make is to not remove their drain plug, or they forget to place their head in the winterized position. Another problem is the lack of information provided. Filters are not meant to be moved once they are installed. If you need to move them, it is always best to drain the filter of all sand prior to this. Do not bring your filter inside at closing! There is no need for this. They are made for our climates, and you doing the draining and placing the valve in the winter position and removing your pressure gauge and backwash line, site glass your filter will be just fine. Some folks will put a tarp over them and there are covers available as well. The filter doesn’t have to be covered.

If you have any questions on this or any other type of filter care and preventions, please contact us at any time. We love to share or knowledge!

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