sand filters

how often do you change the sand in a sand filter at a city pool

In a residential pool, you don't ever need to change the sand unless you've used bacquacil or some other additive that would gunk it up, although you may have to occasionally top it off due to sand lost during backwashing. In a city pool I can't think of a reason why that advice would differ, but the only person around this forum that has experience with large commercial pools is Pooldoc, so he would be the one to answer that question definitively. He's been away from the forum for a couple of weeks, but hopefully will be back soon.

In the meantime, you can log out, go to the main forum page, and then find any post made by me, Watermom, or Pooldoc. In our sigs is a link to the google search feature, which will allow you to search the entire forum and archives for other posts that may give relevant information.

Edit: when new users post, their posts to into a moderator queue and wait for one of us or Pooldoc to approve them before they make it to the forum--it's a step Ben put in place to keep the spammers and hackers off the forum, and it's why you didn't see your post appear immediately. I have deleted the other duplicate post in order to keep all the views and responses in one place.


Welcome to the forum!

thanks Janet
i'am a maintenance supervisor @ the Carlinville city parks and this is the first time I've worked on a pool that large, 600 gal. sand filter lots of trash in the sand like stuff that the basket don't catch. So the backwash wood take that out????

thanks janet

Yes, backwashing will take out anything that made it past the baskets. Just make sure that you backwash until you're getting clean water, then move it to "rinse" and turn it back on for a minute or so to rinse all the backwash water out of the pipes before turning the pump off and switching back to filter. If you skip the rinse cycle, any backwash water still left in the pipes will blow into the pool and make a mess.