backwashed filter for the first time... doesn't feel right


Well-known member
Apr 25, 2021
Pool Size
Liquid Chlorine
Still learning about my first pool and when I bought it, I noticed the pressure gauge was reading pretty high (around 30) but the gauge was cracked. A few on this forum said to replace the gauge with a good one first before doing anything else.

So I did that, and the new gauge was still registering upper 20's near 30. I ran it that way for a while but this weekend decided I would try my first backwash.

Well, I moved the multiport valve over to backwash and ran the pump and watched the sight glass... I saw some debris then it got clearer. Then I went to rinse for a little while. I went to backwash... saw a little debris and ran for about a minute... back to rinse. I did this quite a few times, each time seeing some debris in the sight glass. The problem was that the pool level was starting to run low so eventually as I would try to backwash, the pump was sucking in air from the skimmers. I ran the hose and filled the pool for a couple of hours and then did a few more backwash/rinse cycles. All in all I probably did about 10 although the last 5 or so were relatively short cycles.

The problem is I was expecting the gauge to go to a much lower pressure. I never really saw it go way down like I was expecting. I tried moving it over to filter and saw it was around 20. I did some more cycles. Eventually I gave up and just went ahead and added about 5 lbs of DE into the skimmer, but I never got a good feeling that the filter was really cleaned and really putting on fresh DE.

Right now the pool is still clear and the pressure after adding the DE is about 22. So I figured I will run here for a while. But am I doing this correctly? Is my gut feeling out of place?


Bronze Supporter
Jul 14, 2017
Jenkintown, PA
Pool Size
Liquid Chlorine
Thats a lot of cycles. When i backwash its maybe twice for a couple minutes each with a rinse in between…then new DE.

it sounds like you don’t know what your filter pressure is when its clean. Next time open up the filter, get all the old DE out and see what the pressure looks like when you know its properly cleaned out. That should be done somewhat regularly (at least annually) anyway.
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