How Often Change Sand in Sand Filter?

[dino1956]

I get a ton of different answers. Some say 5-6 Years, others 10 Years & others say 20.
What is the correct answer. I Backwash & Rinse Once a Week, sometimes twice.
We did have 2 Hurricanes in the last 6 years.

 

[jblizzle]

Every 1000 years.......

Seriously, it does not wear out. If you keep the water balanced you never will need to replace it. Only reason to replace is if you get bad calcium scaling. You should be doing a cleaning of the sand like this every year or so:
my-sand-is-channeled-how-to-fix-it-t7626.html#p60821

 

[linen]

Jbliz beat me but here are my 2 cents:

The general consensus on this board is that it does not need to be changed. The sand does not wear out.

A couple of exceptions that might warrent a sand change out are:

• 1. Inheriting a filter and not knowing if the right amount or right kind of sand is in there.
  2. Hard clumping due to high calcium (again not common when a pool is properly maintained)
  3. If the sand is really impacted with oily residue from sunscreens, etc. (this is unusual in a properly maintained pool).

The last two can be observed when doing a a filter cleaning...so for the vast majority of filters, no need to change.

Are you having a problem?

 

[dino1956]

Well I'm having Chemical Problems right now, because I just started taking care of my Pool myself. But that's another story.

But sometimes the Water does not look as clear as it should be.
Someone told me the hard edges of the sand wears out after time & it does not catch the smaller particles.

I have other problems with high CYA, but that's nothing to do with my Filter. I was just curious. My old Pool guy said the same thing. Hardly ever or after 30 years, but everywhere you read online they say 4-5years. Not that I believe everything I read online.

 

[jblizzle]

just what you read here ..... online ..... right ....

The only time the sand even moves is when you backwash ... the sand on beaches moves a lot more than that and it does not turn into powder ...

 

[Speedo]

You should be doing a cleaning of the sand like this every year or so:
my-sand-is-channeled-how-to-fix-it-t7626.html#p60821

I need to do this.

I won't be replacing the sand until there is a reason. I've backwashed maybe 5 times since the beginning of last season, once so far this year. I take advantage when the rain provides the excess. It never runs dirty for very long.

 

[dino1956]

jblizzle, here's one of the quotes I read:

Rule of thumb is to change out the sand about 5 to 6 yrs. At that 5 yr. time frame the sand looses it's ability to hold the contaminents. The shear motion of the water will,in time, round out the sand particle - thus removing the sharp edges that sand naturally has.

 

[jblizzle]

It is bunk ....

There are hi-resolution photos somewhere in the forum of old and new sand ... no difference.

 

[duraleigh]

Rule of thumb is to change out the sand about 5 to 6 yrs. At that 5 yr. time frame the sand looses it's ability to hold the contaminents. The shear motion of the water will,in time, round out the sand particle - thus removing the sharp edges that sand naturally has.

balderdash! :lol: Save your money.

 

[Isaac-1]

I don't know where it was, but there was another link on here where someone compared old pool filter sand under a microscope (not the link above) from multiple filters, and the only sample with detectable amounts of wear came from a commercial pool that was over 30 years old that still had its original sand in the filter. Even then it was their general opinion that the wear was not a major factor.

Ike

 

[jblizzle]

I don't know where it was, but there was another link on here where someone compared old pool filter sand under a microscope (not the link above) from multiple filters, and the only sample with detectable amounts of wear came from a commercial pool that was over 30 years old that still had its original sand in the filter. Even then it was their general opinion that the wear was not a major factor.

Ike

I don't remember that one, but would like to bookmark it if you find it.

 

[linen]

There are hi-resolution photos somewhere in the forum of old and new sand ... no difference.

Link in my post above.

 

[dino1956]

Ok. I believe you all! It amazes me how people try to talk you into wasting your money. God knows, my money will be going to the Clorox foundation if I don't drain my Pool.
CYA 122 (Store Test).
Waiting for my Test Kit & then I will Retest it the Correct way.

 

[jimhokie]

One other thought...it's not the "sharp edges" of the sand that traps particles, it's the small spaces between the grains that limits the size of particles that can pass through. If the sand does in fact "wear", that means the grains would get smaller over time, which in turn means the spaces between the grains get smaller. Therefore, "worn out" sand would actually make for a tighter filter medium, catching smaller particles. This is the principle behind adding a small amount of DE to a sand filter to make it tighter--the smaller DE grains fill in the larger gaps between the sand grains.

The question I've always wondered about is if I'm losing a small amount of sand during backwash that may need to be replenished after some time.

 

[jblizzle]

I think it is possible to lose some sand while backwashing if it was over-filled and/or you had a very strong pump. But generally, I do not think this is a problem.

 

[duraleigh]

Therefore, "worn out" sand would actually make for a tighter filter medium, catching smaller particles

Exactly. Except that theory is not as profitable as the other one .

Both ideas sound good on first thought and neither has any real practical application.

The forum suggest once yearly to open the filter and check for debris on top of the sand bed and have a "looksee" at your sand. It is theoretically possible to need a top off but I haven't after eight years.