Air bubbles out of jets when first turning filter on

[Annorax]

Hi all,

I have a DE filtered in ground pool. This probably isn't new, I'm just noticing it now, but I see that when I first turn my filter on, for the first 10 minutes or so, air bubbles come out of my 3 return jets (though mostly from one - the farthest one from the filter). I haven't seen any noticeable water loss and my filter seems to work fine, with pressure between 15-20.

I'm pretty sure when first turning on the filter, some air bubbles are expected, but it seems to take about 10ish minutes for them to clear and they mostly are coming from the farthest return jet. My guess is that the DE filter tank is filling up during this time (is that amount of time normal?), but I don't know if there's a bigger problem here.

Is what I'm seeing normal? It's an older filter with older tubing so it's possible there is some leak. I'm just really hoping it's not the underground tubing again. I had an issue last year where the water level would drop a lot when running the filter and one of the jets (again, the farthest one) was blowing dirt into the pool at the start, but I had that professionally fixed and those issues went away.

 

[mas985]

Bubbles out of the returns are only really expected if you have solar because part of the return line may drain. Also, tiny bubbles are expected when a SWG is running. Otherwise, you really shouldn't expect any bubbles out of the return.


Can you see any air in the pump basket?

After all the air is purged out of the filter and you turn off the pump, can you hear air bubble up through the filter?

 

[Annorax]

Thank you for the reply. I don't have solar nor an SWG. I had my pool professionally closed today and they said it's most likely minor leaks in the tubing around the filter (since it's very old) that lets a tiny bit of air into the system.

A related question - now that the pool is closed, for a little bit after closing, I noticed a few tiny air bubbles sporadically appearing. They are quite small and not constant (maybe every few minutes, a tiny stream of them). After an hour or so, they've stopped. I called my pool guy who said this is nothing to worry about but if he wanted me to, he would come back sometime and put new plugs in. Is he right and there's nothing to worry about? I've been using this same pool company for years and they always do a good job, I'm just paranoid now since last year I had to repair a broken line.

 

[mas985]

Did the closer put in anti-freeze? If so, there should not be a problem with small leaks.

 

[Annorax]

I saw him putting anti-freeze in a few various places into the filter but I don't know if he put it specifically into the lines. Would doing this cause it to eventually trickle into the lines?

I also put some food coloring around the closed return jet to see if there was a leak around it. Aside from the food coloring slowly sinking and slowly drifting to the left, it wasn't moving around so I don't believe there's a leak - maybe there was just a little bit of air escaping from the newly covered return jet, but with no more air bubbles and no visible link, I'm cautiously hoping that I am OK.