I have an inground pool with a Pentair Sand Dollar filter. I recently had some sand getting into the pool, so I called a service tech. He recommended changing the sand, as it is 4 years old and I run the filter all winter. I ordered a new stand pipe and laterals. The tech emptied the sand, and put in the new stand pipe and laterals, inspected the valve and gaskets, replaced sand. This was an experienced pool tech I have used before. For a couple weeks I was getting a small amount of white very fine sand accumulating on the bottom. I ran my robot vacuum every 3 - 4 days and got about 2/3 cup of pure white very fine sand. To try and address this, I backwashed and rinsed last night. When I restarted the filter, it dumped several pounds of larger grain brownish sand back into the pool (this looked like the bags of new sand he added). Any ideas what might be causing this? Perhaps the priming flow rate is too high on restart? Too much sand, although we put in 350 lbs as the data plate says? Not sure what to try next.
Sand In Pool After Replacing Stand Pipe and Laterals
- Thread starter greg_bowen
- Start date
- Jun 22, 2014
- 52,053
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to TFP! 
I'll start this thread by saying your experienced tech really did not need to change sand. Sand doesn't wear out. Did you confirm if the tech filled the filter partially with water before adding the new sand? If not, he could've damaged a lateral. What about the sand? Which brand? Are you able to confirm if it was #20 silica pool sand?
As to backwashing, that should've been done immediately upon adding the new sand. A VERY thorough backwash followed by a very thorough rinsing. If you have any doubt, I would do both again to see if any loose particulates from the sand were finally washed away or have settled properly in the filter.
Let us know.
Also see ----> Pool Care Basics
I'll start this thread by saying your experienced tech really did not need to change sand. Sand doesn't wear out. Did you confirm if the tech filled the filter partially with water before adding the new sand? If not, he could've damaged a lateral. What about the sand? Which brand? Are you able to confirm if it was #20 silica pool sand?As to backwashing, that should've been done immediately upon adding the new sand. A VERY thorough backwash followed by a very thorough rinsing. If you have any doubt, I would do both again to see if any loose particulates from the sand were finally washed away or have settled properly in the filter.
Let us know.
Also see ----> Pool Care Basics
Thanks for the reply. I saw him 1/2 fill the filter with water before putting the stand pipe and laterals in. It was #20 silica pool sand, and he put two rubber gloves over the pipe so no sand got inside.
