Just checking with you regarding my sand filter...

[Haley]

Hi all!

So, I'm on day 5 of managing my new fill and it's going well thanks to TFP. My latest question has to do with my sand filter...

The day I set up my Intex 1600 and backwashed it, the water wasn't really dirty in my view bubble, which seemed odd to me since it was my first backwash; just a little cloudy.

So today I noticed that my pressure creeped up to about 7, and after consulting my instruction DVD that came with my filter, it said backwash when pressure gets to 7-10. So I just backwashed, (still not really dirty) and it's back down to 5 (which is the same pressure as day 1). The DVD indicated that 5 was normal pressure to return to after a backwash.

-Why doesn't it return to 0 after backwashing?
-Is the fact that my sand isn't really dirty indicative of anything going wrong? Like, is it not cleaning like it should? Maybe I'm expecting too much of my little sand filter?

Thank you!

 

[woodyp]

All filters keep some pressure on them in order to operate. They only go to zero on the gauge when the pump is off. 5 is your clean pressure and 7 is your dirty looks like.

 

[JasonLion]

Everything you describe is fairly normal. The pressure doesn't go down to zero because it includes the back pressure created by the plumbing, as well as the pressure from a dirty filter. When you clean the filter the filter pressure goes way down, but there is still back pressure from the plumbing.

The main indication of clean/dirty when backwashing is transparent/opaque. The water will be cloudy when it is dirty, but not necessarily black, white is quite common.

 

[Haley]

Thank you, WoodyP and JasonLion- that makes complete sense when you explain it. I have no working knowledge of things like this. Can you tell? Thanks again!