Do I have a filter problem?

[mriddell]

I have seen this usually daily since pool opening/construction a year ago. I brushed off the sand about three hrs ago. Last backwash about a week ago, pump is running it's usual schedule, I did discuss with my builder, who discounted it. I've seen threads regarding broken laterals, but obviously don't want to dive into the sand filter if not necessary. What do you guys think?

 

[mknauss]

Can we assume that is in a shallow area that your pool sweep does not get to?

 

[mriddell]

Yes.

 

[mriddell]

Leading out of the return on a sun shelf.

 

[Lake Placid]

Any lingering issues with cloudiness or the pool not clearing as quickly as it once did if….it does cloud on say high bather loads?

 

[mriddell]

No. No worter or clarity issues. No bathing as of yet this year, but none previously.

 

[Lake Placid]

Any other areas near returns that you see sand? Where is this return in the loop, first, middle, last?

 

[mriddell]

Not sure where this return is in the loop, but it is nearest to the pump and equipment. Other returns are returning to deeper areas of the pool and not as noticeable.

 

[Lake Placid]

Not sure where this return is in the loop, but it is nearest to the pump and equipment

It is likely this is the first return in the loop, but it’s hard to tell definitively unless you saw the plumbing when it was installed. A couple of things you can try. Change the direction of that return and see what the sand pattern does with the new change in direction.

Waterco does not provide a freeboard dimension for your filter in any of the documentation I’ve found. However they do provide a recommended sand bed depth of 13.4 inches. You could remove the mpv and measure the bed depth. Top it up to the required 13.4 inches if necessary and run the pool for a period of time. If sand continues to appear after some time, open the filter and remeasure the bed depth. If it’s less than what you put in, it’s time to remove the sand for a full inspection of the laterals.

Now it’s possible the builder overfilled the filter with media in which case sand will push out until it drops to the proper level, however that’s usually visible on the backwash side, not the pool side.

 

[mriddell]

Thanks. I'll pull the valve off the top in the next week or. Thanks for a logical approach. Sound s better than pulling all the sand out to check laterals.

 

[Lake Placid]

I’d start by simply changing the direction of the return. If the sand pattern doesn’t follow, or changes slightly it’s likely environmental. If the sand pattern shifts heavily, moving exactly to the the direction you shift the return, then pull the mpv and measure the sand bed etc…