Sand Filter Guru Needed

[woodyp]

I have a 22" 250 lb. sand filter that I've cracked open to clean before using it again on a new pool. I've cleaned it a time or two over the past 12 years.
Question: How far from the bottom of the neck of the filter should the sand be? Pretty sure I've lost some over time. Ain't exactly like there's a "fill to here" mark"!
It is an Astralpool filter, I have the manual, and it says NADA of course.

The first one to tell me just to weigh the filter gets BANNED! ( I know you're out there)

Thanks,
Woody

 

[Texas Splash]

If you can't find the actual specs, a general rule of thumb is about 2/3 full of sand. But let's look to see if anyone has those specs.

 

[Newdude]

The first one to tell me just to weigh the filter gets BANNED! ( I know you're out there)

No. No. I'd never. Just buy six 40 lb bags for a 250 lb filter and it'll probably be close enough to 2/3 full.

(I'd start new for the cost of sand)

 

[woodyp]

It's about 11" from the top of the stand pipe. I'm thinking about 6 inches would be normal. Trying to figure out how much sand to add back for another 4 or 5 inches in depth. My Google Foo ain't working!
I ain't replacing it all. That's sacrilege around here!

 

[woodyp]

No. No. I'd never. Just buy six 40 lb bags for a 250 lb filter and it'll probably be close enough to 2/3 full.

Yes. Yes. You would!

 

[woodyp]

After measuring the height from the bottom of the filter to the top of the stand pipe at 23 inches.......the 2/3 "rule" would put me about 3 inches shy of where that would be. It would suggest 8" from top of stand pipe, and I'm at 11. To bag or not to bag.....THAT....is the question!

 

[Newdude]

To bag or not to bag.....THAT....is the question!

Add 2 (or all 3) of the 3 inches and see how it does. Anything I've ever read regarding sand said *about* 2/3, so i don't think the exactness is all that important.

 

[1poolman1]

I have a 22" 250 lb. sand filter that I've cracked open to clean before using it again on a new pool. I've cleaned it a time or two over the past 12 years.
Question: How far from the bottom of the neck of the filter should the sand be? Pretty sure I've lost some over time. Ain't exactly like there's a "fill to here" mark"!
It is an Astralpool filter, I have the manual, and it says NADA of course.

The first one to tell me just to weigh the filter gets BANNED! ( I know you're out there)

Thanks,
Woody

Per Hayward and Pentair schools from years ago, the "freeboard" (no sand) in a sand filter should start at the top of the cylindrical portion of the tank.

 

[woodyp]

That would be at rhe exact top of the stand pipe which is only an inch or two from the top of the lip.

 

[1poolman1]

That would be at rhe exact top of the stand pipe which is only an inch or two from the top of the lip.

While this seems to be for a smaller filter, the principle should be the same. Page 6.

 

[woodyp]

FYI....50 Lbs. of sand worked out to be about 4" inches worth in that 22" filter. Left 7" of free board to top of pipe. Thanks folks.

 

[Bama Rambler]

The general rule of thumb for vertical sand filter sand level is just at, or a little below, the tangential line (where the straight wall meets the dome shape top), unless otherwise stipulated. That way the maximum surface area of the sand bed is maintained.

 

[woodyp]

I'm definitely below the "transition" by a tat.

 

[JamesW]

 

[woodyp]

I'm assuming the filter will be totally full of water while operating?

 

[JamesW]

I'm assuming the filter will be totally full of water while operating?

Correct.

 

[JamesW]

Here is a video explaining about Freeboard.