Small amount of sand in pool everyday

[mtech]

Hi all - found my way back to TFP after years of following this method and chemgeek's advice with my hot tub. I purchased a new home and now have a pool to manage.

At the beginning of the season before opening, I removed all equipment and poured a concrete equipment pad. I had emptied and cleaned the filter as part of its removal. I inspected the laterals and nothing seemed out of the ordinary, but didn't study them. Upon reconnecting everything, I accidentally put too much sand in the filter. I goofed and added 350lbs, and later realized the label only calls for 300lbs. I used quikrete pool filter sand. I don't recall having this problem last season, but as a new owner of the home, I only managed the pool for about a month before it was closed for winter, so I don't have a lot of history on this pool. Full details of my setup are in my signature.

I've have what seems to me as good filtration, as all of the haze was filtered out the 1st week of open during my SLAM. I can see the screws on the main drain cover from above. I am having a small problem with sand on the floor, collecting in spots such as the liner seams and creases. This sand quickly disappears if you sweep your foot over it. It is also quickly collected when I vacuum or send it the dolphin robot. Sand does not appear when the filter is off overnight.

Questions (and thanks in advance for any suggestions!)

• Could sand on the floor be attributed to me adding too much sand to the filter? If so, what is a good way at my stage to calculate and remove 50lbs with the sand being wet?
• Is this escape be due to new sand media? Are there fine particles in these bags that can pass through the laterals?
• I have not vacuumed to waste, as I don't have a good place to position my backwash hose running for more than a few minutes. Is it possible I'm caught in a loop picking up the same particles? Not sure what the dolphin is doing, because after it runs, I don't see any sand at the bottom of pool, but there isn't much sand in its trap... though there is some.
• I've read about adding some DE material to sand filters to increase their efficiency, but am not sure if this advice is applicable in my case.

 

[Texas Splash]

First question I have to ask .... are you 100% sure what you are seeing is sand and not algae? It seems awful dark in the pics to be sand. Does it feel gritty? If you have any doubts about it being algae, do an Overnight Chlorine Loss Test first.

Now if you are sure it's sand, there are a few possibilities:
1 - We've seen poor feedback about Quikrete pool sand. It is sometimes too fine and slips through the laterals.
2 - Overfilled? Perhaps. If you chose to open the filter, remove 3-4 inches of sand so that you can be confident it's not right up against the MPV.
3 - A lateral could be loose or damaged. Did you add water before "slowly" adding the sand?

 

[mtech]

Thanks for the reply Texas Splash!

You bring up an interesting point about confirming what I am seeing. I saw this post early enough where I was able to run out in the morning and take a FC reading. I compared it to the result I logged from last night and it only differed by .5 PPM. Although the picture shows the spots to be fairly dark, in person, they appear to be what I'd imagine my sand media to look when wet. The quikrete sand was a dark yellow/beige color. The spots are gritty to the touch.

I did add water to the filter before adding the sand, and as a unplanned 2nd layer of softening the fill, my son found it fun to hold his hand out while I was pouring in the bags of sand. I also capped off the center pipe while doing this work. Going by memory, there were a few inches of empty space before the top of the filter.

I'm thinking that at this point, the only thing I would do would be to possibly attempt to remove some sand. If that does not remedy it, I'll wait until the end of the season to empty, inspect, and fill with another brand of sand.

 

[mtech]

As another data point, when backwashing, I run in backwash mode until the sight glass is clear. I then shutdown and change to rince. At this point, the sightglass fills with some sand. Is this normal for rince?

 

[Texas Splash]

At this point, the sightglass fills with some sand. Is this normal for rince?

For short periods yes. Eventually the glass should go clear, then maybe give it an additional 30 seconds or so on rinse just to be safe before going back to filter mode.