Broken air relief tube Hayward S200. What does it do?


New member
Aug 10, 2014
Lincoln, Nebraska
Hello TFP, this is my first post on this site! Let me know if there is anything I'm leaving out, or if this isn't the right place for a post like this.

I was wondering if anyone can explain what the air relief tube does in my Hayward S200 sand filter?

The reason I ask is because I just changed the sand in my filter over the weekend, and found out that the existing tube was broken near the bottom, and a pit was being formed in the sand right above where the break was, as you can see in this photo.


I have a feeling that this was causing an issue with the filtering capability of my pool, but I don't know the purpose of the air relief tube, so I am not sure exactly this might have been affecting it.

Once I got all the sand out of the filter with a shop-vac, I inspected the laterals and everything looked okay except for the air relief tube, which I was able to replace with parts from Lowes.


The reason I changed the sand in the first place was because my pool has been cloudy for the past 3 weeks, even though it looks really blue and my levels are all in range (PH 7.3, CL kept around 5, TA 100).


I think I'm on the right track now though, I'm checking levels every day and adding chlorine with 8.25% Clorox when needed. I've been brushing the whole pool every day for a couple weeks now. Since I changed the sand on Sunday it has cleared up just enough to make out the pattern on the bottom of the pool in the shallow end. I think by the end of the week if it isn't really noticeably clearing up I might try adding DE again like I did before changing the sand, but I'm optimistic that I won't have to with how it is going so far.


TFP Expert
Feb 3, 2014
Central Minnesota
The air relief line allows an easy route for air to escape sand instead of causing channels in the sand like you had near that break.

I'd be concerned with the cloudiness. Post full test results and consider an OCLT to make sure things are OK.


Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
Tucson, AZ
Well, you just replaced all the sand (not likely necessary), so the filter was full of air at that point. Now it all needs to be purged by running the filter. You could also introduce air when you backwash.

I agree with JVTrain ... cloudy water is generally a chemistry issue and not a filtration issue. Post up a full set of test results. Specifically, what is your CYA level? That determines what is the required FC level according to the FC/CYA Chart.

- - - Updated - - -

Oops. Just saw you are only using test strips. That is not going to cut it. Seriously consider investing in one of the Recommended Test Kits if you want to understand and control your pool.
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