Filter not doing the job?

[gogolion]

Hmmm, maybe I'm not getting good suction.

Is there a way to measure that? It feels pretty strong to me on my hand, but then again I have nothing to compare it to. I think I have a 24" vacuum head and I definitely do not get suction the entire length of the head. I really only cover a few inches wide with each pass of the vacuum. I plug one of my skimmers when I vacuum to get better suction. I guess I'll also try turning off my main drain. One thing I've never understood, which could be a cause of poor suction, is that air always seems to get air in my system when I vacuum. Air is always gurgling out of the returns. I have no idea where it comes from since no air gets in when I am filtering normally. I always make sure my pool is full (middle of skimmers) before I vacuum.

[PoolDoc]

One thing I've never understood, which could be a cause of poor suction, is that air always seems to get air in my system when I vacuum. Air is always gurgling out of the returns. I have no idea where it comes from since no air gets in when I am filtering normally.

Sounds like a suction leak. If it is, it will probably get worse when you close the main drain. And, a suction leak will definitely impair vacuuming.

However, using a 1 1/4" hose, instead of a 1 1/2" will mess vacuuming up, as well. Also, stiff vacuum heads sit too high above the surface, and not create the high flow / high suction necessary for good vacuuming. The ProVac heads conform to the pool surface much better than any others I've used.

[gogolion]

I went to the pool store today to get a skimmer sock. They guy there said the skimmer sock won't catch fine particles such as algae. Instead he sold me some cullulose fiber DE replacement that you put into your skimmer to help your filter grab the fine particles. He said to add it 1 scoop at a time to my skimmer until the pressure goes up 1psi. I told him that my pressure never seems to increase and he said I may need more or new sand. So I went home and after adding 5 scoops my pressure didn't budge. I called the guy and he said add 2 more scoops and if it still doesn't move then I probably have a problem with not enough sand or needing new sand.

Can the kind folks here please give their opinion on the pool guys' diagnosis? If I do need to add sand or new sand is there a guide on this site somewhere of how to do that?

Thanks in advance

[PoolDoc]

Did someone here suggest a skimmer sock for you? They definitely won't remove algae.

Cellulose fiber may gum up your sand, but you can remove it when you work on the filter. Doing so is a pain on top mount filter -- you have to cut the plumbing, before you can unscrew the valve!

There's a good chance your pump is too big for your filter, and has been blowing sand out every time your backwash. You'd have to give us actual pump and filter model numbers to be sure.

[gogolion]

Yes, earlier in this thread someone suggested skimmer socks. Luckily the guy at the store steared me away from that.

Here are my model numbers:
Pump: Pentair model SF-N1-1-1/2A/340039
Filter: Pentair Tagelus, Part #145241

Please let me know if they are mismatched.

This equipment was all installed this year by a pool company. I'm probably under warranty if it is malfunctioning or was installed incorrectly.

[PoolDoc]

Pump: Pentair model SF-N1-1-1/2A/340039 = 1.5 HP Pentair SuperFlo (curves)
Filter: Pentair Tagelus, Part #145241 = TA60D 24" top mount sand filter, maximum desirable flow, 45 GPM

To give you a comparison, I run a 36" filter (2x the filter capacity) with a 1.5HP Hayward Super pump which has the same curve as your pump . . . and it is PLENTY big enough, even though it has to run a high restriction fountain!

You'd probably be better off replacing the impeller, diffuser, and seal, and dropping back to 3/4 HP performance. You'd cut your electrical bill by 35% or more . . . and you'd be able to filter fine particles. As it is, you have so much flow and pressure, you just force the fines through the filter!

[gogolion]

So what should I do? Call the company that installed the equipment at the beginning of the season and tell them they sold me a pump that was too big? Of course they're going to tell me I don't know what I'm talking about. I'm kind of in a bind here.

Oh and BTW, on the side of the pump it says it is 1.65HP.

If I go to a smaller pump will that give me less suction when I vacuum?