Sand Filter not performing

[Patrick_B]

I began running a Hayward 13" AGP sand filter last year and it performed very well. This year, it is losing flow much, much earlier, with no change in load or pool care issues. When in need of backwash, the PG will indicate 5 PSI, and this has been the case since new. It is a small motor/filter setup, so Im not worried about that. What is an issue, is the very short run times. It seemed to be 10-12 days, and at least a few vac sessions between BW times. Now I get one vac at best, and or a few days run time before I lose flow.

Before I tear into it it, I wanted ask for opinions. Is this channeling, plugged lateral (slotted bulb in this case), something else? Any thoughts would be appreciated.

 

[Richard320]

I'd guess the sand is crusted up into a solid mass. Texas is known for hard water. Probably opening it up and poking around with a dowel or a garden hose to break up the clods will fix things.

 

[duraleigh]

My bet is your water chemistry is out of whack so your filter is doing what it is supposed to do.....trap the particles (dead algae). It simply has more particles to trap so is plugging up sooner.

On an unrelated subject 5 psi for backwash pressure indicates a restriction on the suction side of your system or a broken gauge

 

[Patrick_B]

My bet is your water chemistry is out of whack so your filter is doing what it is supposed to do.....trap the particles (dead algae). It simply has more particles to trap so is plugging up sooner.

On an unrelated subject 5 psi for backwash pressure indicates a restriction on the suction side of your system or a broken gauge

I have wondered about the gauge from the beginning, as it is a cheapy. However, it has only shown 5 at BW time since early on, and I just think the pump wont put out much pressure. I have not looked hard, but have not found a low pressure range gauge to realace it with. But again, it is a tiny little setup. I am certain there is no obstruction however.

As for chemistry, I am a zealot about my Chlorine testing and am dead certain there has been no issue with algae. Please don't take the comments as defensive, I respect your opinions very much Dave. It just really seems like something mechanical here. I do have hard water though, and I will just have to see what I find when I open it up. There is very little area for water to pass through on the slotted bulb and Im really curious if this has become scaled or fouled with sand particles.

 

[stev32k]

I had a similar problem two years ago. The filter just was not performing like I thought it should so I opened it up and started flushing with a water. I made up a lance from 1/2" PVC pipe with a hose connection on one end that was long enough to reach the bottom of the filter and used that to drill down. The water coming out looked like chocolate milk for about 30 minutes. There were lenses of a hard crusty material that I could not break up with the lance and had to dig out by hand. It was amazing the filter worked at all. When I finished cleaning I had to replace about half the sand.

I now do that every year as a routine maintenance item. I believe it prevents a lot of problems that are hard to diagnose.