New sand not filtering enough?

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Posts: 126
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My Pool: HOA Community Swimming pool built approx. 1971.
In-Ground, Plaster 34x18 3.5-6' deep, Sta-rite P2R A5D-120L pump, A.O. Smith centurion 1HP (uprated 1.25HP) motor,Hayward S244S filter(new 2011), Rainbow Lifegard Chlorine/Bomine feeder; new replastered June 2010
Location: Houston, Texas USA

New sand not filtering enough?

Postby Henry_R » Thu 25 Aug, 2011 11:34

What are signs that filter sand might be channeled and/or just not filtering right? Filter PSI is 12.5 which is the same as it was with the old filter and seems to be the nominal pressure. This is where is settles after backwashing so I gather it's proper.

Our HOA pool sand filter which was a triton II and upwards of 15-20 years old was replaced over Memorial Day weekend this year. The pool man who is no longer employed by the HOA put the unit in. He was fired after three agae blooms in 8 weeks and his only solution was to drain the pool and refill, then no call backs.

Since the second week of July we have been taking care of the pool service ourselves since we cannot find another pool service who will take on a new client in the summer season during extended drought and triple digit heat. Pool was drained due to high CYA and calcium twice to bring CYA <100 and we have it now at around 50-80. My test with a TFT100 kit reads CYA=50. Pool stores test higher at 90. :roll:

Anyway, we've had some issues with calcium based 73% chlorine shock clouding the pool (Leslie's pool has appearently had some issues with this product this year, or so they told us) and other cloudy pool issues not related to water balance. All readings were normal, but the water was cloudy requiring a clarifier which also didn't help all that much. The cal-hypo took 5 days to cycle through the filter and begin to clear running 12 hours a day. We've been using 10% chlorine liquid since this issue cloudy water issue.

Shouldn't the filter be able to filter calcium powder out in less than 5 days? The filter specs say the water flow rate should be 62 gpm. With 21000 gallons that's under 6 hours for a full turn over. But does this number include the main drain (which is inoperable in our pool)? If so then our turnover is lower, but by how much with only one skimmer?

I'm wondering if the filter sand might be the wrong type (I saw the empty bags and they were labeled Filter Sand, but that's all I can remember), perhaps wasn't leveled properly during installation, and/or perhaps the sand has channeled and needs to be levelled? I could open the top, but I don't want to damage anything.
Do new hayward filters have threaded on caps under the clamp?

Also, since we don't have a functioning main drain (plugged in 1980s) and depend on the skimmer I cannot backwash too long or we'll have to refill which we cannot do except limitedly due to mandatory water restrictions. The backwash water is very white in color though and I cannot really backwash it long enough to get it clear. Is this the problem not backwashing long enough to clean the sand fully or something else?

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Location: Rockwall, TX

New sand not filtering enough?

Postby allclearpools » Mon 28 Nov, 2011 17:11

Some shock contains by-products that will suspend into the water and make it milky. THe best thing to do is flock the pool water with alum or use liquid flock (2-3 times the normal dose). Then the sand filter will be able to catch the particles as long the send was installed correctly. What debris that is left on the bottom can be vacuumed on waste (multi-port valve) or with a portable pump. Also this can happen when new filter sand is installed and not backwashed as soon as the pump is started the first time.

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