Filter sand in pool

[DeadAquaRite]

Need advice. In an effort to stop sand in my pool, I have taken the steps below without success.

1. Emptied filter.
2. Inspected laterals (no problems observed)
3. Replaced 2 laterals I broke trying to remove them.
4. removed and inspected all internal plumbing (no problems observed)
5. Replaced sand with Leslies filter sand.
5. Put a thin layer of teflon tape on all internal threads, retightened to finger snug.
6. Removed and replaced the spider gasket.

And I STILL have about 1/2 cup per day of sand in my pool, mostly on the steps. And when I backwash I lose 1-2 cups of sand, consistently. Any ideas?

 

[borjis]

What make/model is the sand filter?

Someone with a Hayward S244T had that same problem you had and found that the laterals (both new and old) could
accidentally be folded in such a way that sand would escape. (he was looking up at the bottom of the assembly)
There were significant gaps for sand to escape.

 

[DeadAquaRite]

I've got a Pentair Triton II side valve. I'm not sure what you mean by "folded" My laterals thread into a round hub. Like this:

 

[duraleigh]

I assume you made sure your center standpipe was seated properly.

Spider Gasket went in nicely with little struggle?

How much "freeboard" space beween sand and top of filter do you have? It should be 11.25"

How big is your pump?

I have had that filter (in a larger version) for 10 years and it has been bulletproof. I am at a loss why you have been so thorough and still losing sand.

 

[DeadAquaRite]

I assume you made sure your center standpipe was seated properly.
Spider Gasket went in nicely with little struggle?
How much "freeboard" space beween sand and top of filter do you have? It should be 11.25"
How big is your pump?
I have had that filter (in a larger version) for 10 years and it has been bulletproof. I am at a loss why you have been so thorough and still losing sand.

Standpipe: It appeared to be. I threaded it on until it started to resist. Not sure I understand, so explain in more detail.

Freeboard is 11.25", or was when I finished. Pump is 1.5HP, same as always. Sand just started last season.

Spider gasket went in painlessly, once I got the old one out. Problem appears not to have changed with any "fixes".

 

[duraleigh]

I am at a loss.

 

[CNJ_EC]

Dead,

Did you check the Connector Air Relief Tube?

 

[DeadAquaRite]

Dead,
Did you check the Connector Air Relief Tube?

You mean the skinny tube that sucks air from the top of the filter? Has a screen on it? It was inserted and the collar locked. Nothing looked amiss.

 

[CUTiger78]

Even though I've got a Hayward S244T and you've got that Pentair, I've got to think that any filter losing 1 or 2 cups of sand per backwash has got to have something wrong with it. Sometimes I might lose a teaspoon, sometimes none.

Does rinsing for 30-60 seconds after backwashing make any difference in the amount of sand that gets back into the pool?

Good luck!!!

 

[CNJ_EC]

Dead,

It is a Triton II Series ... correct? The lat looks like it's from a TR100 series

 

[VikingPoolMan]

Could be a hairline crack in the standpipe (or laterals)... some times, these types of crack are very hard to see - especially when everything is off and there is no pressure in the system. However, when the pump is running, the crack widens and could be causing the problem.

 

[CNJ_EC]

VikingPoolMan,

This model doesn't have a standpipe ... it has a lower pipe assembly .. sort of a 90(to the lower lat) with a 12'' straight section of pipe to the outlet flange. But it could be a possibility! Good point!

 

[DeadAquaRite]

It is a Triton II Series

Yes, it is. I just grabbed that photo to show how my laterals were arranged.

Does rinsing for 30-60 seconds after backwashing make any difference in the amount of sand that gets back into the pool?

Doesn't appear to. In fact, nothing appears to change net sand in.

sort of a 90(to the lower lat) with a 12'' straight section of pipe to the outlet flange. But it could be a possibility! Good point!

Correct. Vertical about 8-10in, then right 90° to exit the filter housing. Top is a mirror image vertically, except with a diffuser hear instead of laterals.

I guess I'm going to have to tear this thing apart again, gut it, and inspect all the pieces. Any suggestions for removing all the sand besides a coffee can? I'm tempted to take out the drain "filter" and wash it all into a wheelbarrow down below.

 

[CNJ_EC]

Dead,

Is it all sand or is the lower a combo of pea gravel & sand? My tandem tr104c have approx 650lbs of sand in the upper cav and 275lbs combo each in the lower lat area ... but I'm not using side of top multi-valves. I used a wet vac to the pea gravel and then scooped.

 

[DeadAquaRite]

All sand.

 

[CNJ_EC]

Dead,

My numbers were 650lbs sand & 250 pea gravel.

My sand was about 3+ yrs old. The primary problem was black sludge occasionally on the return when my VS pump was in cleaning mode and high pressure(25PSI) most or the time ... both issues caused by channeling. Backwashing didn't help so rather than waste time on so called cleaning "tips", I decided to dump it and start anew. My Upper 4 diffusers cleaned off nicely with no problems but the 4 lower lats had a thick layer of sludge so I just replaced them.

I have a 2" drain but it was taking for ever to drain. I wasn't going to reuse any of sand/pea ... so after 30 min ..... I got my 2 wet vac out and the sand was out of both tanks in about 2hrs. Scooped some of the gravel, then removed the sand drain and hosed the remainder out. If you can use the drain ...make yourself a single or double wire rake to help pull to sand out. Once you get to the half-way point ... the remaining sand will run out quickly.

If you have to remove the lower assembly ... take your time removing the flange & flange adapter - you don't want to damage the filter's shell. You might want to have a Var Spd Dremel handy just in case you have to slice the ID of the lower assembly pipe. Mine are different - tandem plumbing kit attaches to the filters inlet/outlet port with unions. A little pressure with the pipe strap and they spin right off.

Oh ... decided to stay with the pea gravel and sand ... no leaks or sand ... and my pressure is steady at 8 PSI. When you add the sand back .... follow the procedures carefully so as not to load down the unsupported Lat & pipe assembly.

Good Luck!

 

[DeadAquaRite]

I was definitely very careful not to load down the lateral assembly. I added about 10 inches of water then slowly add it sand until it's well covered.