DE Filter question

[Paul Kallus]

Hi,

I am starting my 5th year of running a 24 year old in-ground pool and am still learning - problems never end with this thing. I have a Nautilus NS-36 DE filter - and upon starting the pump this past week I noticed a "slushing" sound in the filter drum-barrel - towards the top near the pressure gauge. I took it apart this morning before work and all the grids and manifold looked secure, but noticed the strainer screen was missing from the air vent tube. I am guessing it fell or blew off at some stage of cleaning last season, and is possibly in the bottom of the barrel. Since I was late for work I had to reinstalled the drum and start the pump and get to work. My question is how critical is this strainer screen and what will happen if I don't get one back on soon?

 

[jblizzle]

Welcome to TFP!

Without the strainer, DE and dirt could bypass the grids and get blown into the pool.

 

[Paul Kallus]

That makes sense, thanks.

Another question - not sure if I should start a new post or not, so I'll ask it on this one: I noticed air bubbles in the return water to the pool this season - and I checked the above-grade influent lines for leaks and couldn't find one (but obviously could not check under-ground lines). Where else could air be entering the lines? Is it even possible for air to enter on the discharge part of the pump and filter, or can air only enter on the influent (vacuum) side of the pump? I am thinking the latter which would indicate a hole in the underground influent lines.

 

[jblizzle]

It is pretty rare for the air to be introduced on the pressure side.

Do you have an SWG? Please add your pool details to your signature as described HERE as it will help us help you.

Do you have multiple suction lines? You could try isolating them and see if the bubbles only occur in certain orientations.
Pool School - Suction Side Air Leaks

 

[Richard320]

The most common sources of air leaks as I rate them based on my years of reading here
1) Low water level in the skimmer allowing a vortex to form.

A) Low pool level
B) Sticking weir (flapper)​

2) Cracked O-ring under the pump strainer basket lid
3) Loose pump drain plug / bad rubber gasket
4) Three-way valve seals on the suction side.
5) Threaded fittings at the pump.

Pool School - Suction Side Air Leaks

 

[Paul Kallus]

I'll check those areas around the pump and elsewhere, thanks.

I'll also try to fill out the specs on my pool as suggested.

Its a little sad to say that I think my pool's days are numbered...it'll need a new liner soon, probably new steps, could use a new filter, and I just don't have the time or energy to deal with it. Its become the proverbial money pit. I would miss cooling off after lawn work.