Not enough suction at 1500 RPM?

[Teris]

Hi guys. I just took over taking care of my pool and it's been going okay, but I don't think the suction is working well enough as the pool has looked a little cloudy and there is detritus at the bottom of the pool despite the chems looking good (Leslie's testing).

The pool is about 12,000 gallons. I run my Intelliflo at 1500 RPM for 8 hours, then at 2400 RPM for 2 hours. At 1500 RPM, the crawler doesn't move and there is zero water moving through the skimmer. At 2400, the movement is okay on both. Maybe I'm misremembering, but I think the water used to flow pretty well through the skimmer when it was on 1500 RPM. The filter is clean (I cleaned it only about 2 months ago) and the skimmer and pump baskets are clean. I got a drain king and flushed the pipes fairly quickly, but didn't see any obvious problems. I flushed the air out of the filter and I backwashed for a minute or two a few times. I also unscrewed the valve that diverts the water to the skimmer or crawler and it was clear inside.

Should the crawler and skimmer be moving pretty well at 1500 RPMs? Any ideas to get the water moving better besides raising the RPMs? Thanks very much!

 

[Jimrahbe]

T,

Tell us about your pool or show us some pics of your equipment pad..

Do you have a heater?

I doubt your crawler will run at 1500, but in most pools the skimmer will work just fine.

Just because you don't see a lot of 'action' at the skimmer, does not mean it is not working..

If your look down into my skimmers, they almost look dead.. But I use hairnets in the skimmer, so I can tell what they capture, and they are working just fine..

Do your skimmers have a weir door between the mouth of the skimmer and the skimmer basket?? The weir door is what makes a skimmer... well, SKIM.

Thanks,

Jim R.

 

[Teris]

Thanks, Jim!

My pool has a weir door, yes. It has a heater, but I never use it.

The skimmer basket is catching nothing and I see small debris/pollen float right by it (at 1500 RPM). When I put my hand in there, I can feel the section is very weak.

The second pump is for a waterfall that is rarely used. The old non-VSP pump is out there unattached.

Thanks for your help!

 

[Jimrahbe]

T,

Thanks for the pics..

Anything that the water has to pass through to get back to the pool causes a reduction in flow..

When you have a heater, even if not used, then normally you have to run faster to move the same amount of water if you did not have the heater in the return path.

The key in my mind is... "Did it work before and now it is bad"... If it used to work and now it does not, then what failed?

Let's assume it used to work...

Could be that your pump's impeller is clogged with tree junk... Coming from your cleaner.
Could be that your filter grids are clogged because you used some 'magic' clarifier or Floc from your pool store.
Could be the inside of your heater has rusted away. There are some parts inside the can move and reduce the flow.

Just guessing of course.

What is your filter pressure... at 1500 and at 2400??

Thanks,

Jim R.

 

[Teris]

T,

Thanks for the pics..

Anything that the water has to pass through to get back to the pool causes a reduction in flow..

When you have a heater, even if not used, then normally you have to run faster to move the same amount of water if you did not have the heater in the return path.

The key in my mind is... "Did it work before and now it is bad"... If it used to work and now it does not, then what failed?

Let's assume it used to work...

Could be that your pump's impeller is clogged with tree junk... Coming from your cleaner.
Could be that your filter grids are clogged because you used some 'magic' clarifier or Floc from your pool store.
Could be the inside of your heater has rusted away. There are some parts inside the can move and reduce the flow.

Just guessing of course.

What is your filter pressure... at 1500 and at 2400??

Thanks,

Jim R.

Thanks, Jim.

The pressure at 1800 is 8 (I raised it bc 1500 wasn't doing anything at all).

The pressure at 2850 is 15.

I tried cleaning out the impeller with a screwdriver without taking off the housing, but nothing was in there. Next step may be to take off the housing and clean out the slots in the impeller that are not accessible without taking it out.

I don't think the filter grids are clogged because I just recently cleaned the whole thing very well. I have never used floc or a clarifier.

 

[Jimrahbe]

T,

I think it is pretty normal for people with heaters to have to run between 1500 and 1800 rpm... I run at 1200 rpm, but I don't have a heater.

The question still is... did it used to work well at 1500??? If it did, then something changed.. I was just listing things that 'might' cause the issue..

If it never worked at 1500, it is more likely that you just need to run at 1800 rpm.

I have seen several posts here where impellers being clogged, causing poor pump performance.. But, I have had no direct experience with finding it.

Thanks,

Jim R.

 

[Teris]

Thanks very much, Jim.

It may have worked the same way before and I didn't notice it when I wasn't taking care of the pool. I didn't realize that a heater requires more pressure, but it makes sense if the water has further to travel, it needs more pressure.

I appreciate your help. Thanks for taking the time!