Type of sand in sand filter

[Richard_S]

Hi everyone!

it's that time of year again when the excitement builds as the weather begins to get warmer...and the pool needs to be put back into action. This year I feel I need to change the sand in the sand filter, as it's been in there 6 years possibly 7, can't quite remember. I changed the pump last year and the flow rate/pressure proved to be troublesome (read slow/high), so spent almost an hour flooding out the sand filter tank with a water hose trying to clear the sand...but although a lot of muck came out, I never managed to get clear water and eventually stopped for fear of needing a loan to pay for the water. Seeing that the sand has now had a chance to dry out over the winter, I'm guessing now would be a good time to replace it as hoovering will be simpler.

Question;

1) Local pool store suggests that I should have a "bigger" sand in the bottom followed by a finer sand - is this right?

If I do need to mix sand, what are the ratios and qualities?

if i should use just one sand, apart from the obvious that it needs to be pool sand, is there a particular grain size that I should be using?

thanks for any help,

R.

 

[JasonLion]

You want #20 silica sand, sometimes called pool filter sand. If I remember correctly that is .45-.55 mm.

Commercial pool filters use gravel in the bottom and sand on top of that, but it really doesn't make much difference in the smaller residential filters, so residential filters normally use all pool sand.

 

[Richard_S]

Jason, thanks for the info and reassuring me. I must admit to having come up blank for mixing gravel/sand in a pool filter - every "how to" on changing sand only shows one type being used, so not sure why the pool shop would suggest that I do this, knowing that I only have a residential pool.

 

[Richard_S]

right...changed the sand...all 130kg of it....not a job for the faint hearted even with a vacuum. Filter pressure now runs much lower, so that's a great improvement. I won't be doing that again any time soon but worth doing.

Pool is now shocked, clean, but a little chilly still.

 

[JVTrain]

Hadn't thought about how it would be much easier to change sand in the spring when it's dried out. MUCH easier than trying to get wet sand out!

 

[jackrogue]

You want #20 silica sand, sometimes called pool filter sand. If I remember correctly that is .45-.55 mm. Commercial pool filters use gravel in the bottom and sand on top of that, but it really doesn't make much difference in the smaller residential filters, so residential filters normally use all pool sand.

Ahhh . . . . sand . . . the things we didn't know!

What is Sand Made of? History.
http://www.nature.com/scitable/blog/saltwater-science/what_is_sand_made_of

"The primary component of typical beach sand is quartz, or silica (SiO2)."
http://geomaps.wr.usgs.gov/parks/coast/sand/sand.html

Parrotfish play a significant role in bioerosion while feeding on seaweed and polyps. Their sturdy beaked mouths and pharyngeal teeth grind up coral and coralline algae ingested during feeding. After digesting what is edible, they excrete the remainder as sand --- one fish can produce 200 pounds of white sand per year.
https://en.wikipedia.org/wiki/Parrotfish

Fish Funnies - Parrotfish: The Ultimate Sand Factory
http://www.youtube.com/watch?v=gATMD5RTYmk