having trouble with a cloudy pool

[Watermom]

TR-140 with about 900 lbs of pool sand. Its a big one.

No kidding! That's huge!

[PoolDoc]

I'm surprised your water is not cleaning up rapidly. Definitely, do the DE test. I'm wondering if you got low quality filter sand -- or even sand that's NOT filter sand, such as coarse sand blast sand.

[adambeazley]

I used pool sand from home depot (I believe it said #20 on the bag)... http://www.homedepot.com/p/Quikrete-...5350/202314677 thats all i could find on their website, i cant remember if this is the exact type I bought.

However, the pool was cloudy even before the sand change... I thought the sand change would help.

[adambeazley]

+ Run your filter 24/7

+ Only backwash on a 4 psi or greater pressure rise.

+ Add 2 - 4 cups of DE filter powder (Lowes, Ace, Home Depot, Amazon) to skimmer after each backwash. Watch for rapid pressure increase. Discontinue when pool is clear.

? What size filter do you have?

So I noticed that there is DE filter powder for DE filters and sand filters... Does it matter which one i get? The one you linked to is for DE filters? Does it matter that i have a sand filter?

[Watermom]

The DE that is used to test to see if sand filters are working properly is the DE that is normally used in DE filters. One and the same.

[PoolDoc]

From what we've been able to tell this season, the Quikrete sand is very marginal in quality, and probably does not meet specs.

Definitely, do the DE test.

But also, go ahead and purchase a bag of labeled pool sand from a pool store. Then pop the top on your filter and grab a cup of sand from the filter. Replace the top, allow the sand to dry and then compare. Filter sand quality has at least 4 factors:
1. Range of sizes, within tight limits -- no very fine particles; no large ones.
2. Size -- average size is quite small.
3. Sand grains are sharp edged, not round.
4. Material is quartz, not other minerals.

If you can't tell by eye, take a dark sheet of paper, and spread some of the pool filter sand out in a very thin layer, and then photograph it in sunshine, using the macro setting on your camera. Then, do the same with the sand out of your filter.

If the Quikrete you have is like some of the other that we've seen, you may need to remove and replace the top 8 - 10" to get good filtration.

[adambeazley]

Well I did the DE for Thursday, Friday and Saturday and noticed that the pool continued to clear, but still couldn't see the bottom in the deep end. I stopped using the DE Saturday evening and just left the pump running without adding anything but about 4 gallons of bleach and as of Sunday, the pool it crystal clear.

I also found a small rip in the vinyl at the very bottom in the deep end on Saturday, so I patched it.

Thank you so much for all of the help, I think I've got a good handle on this now.

Thanks!!!

[Watermom]

Great to hear!