Filter pressure gauge conundrum

[dndrich]

Pool Pals:

I have a nice Jandy CL-580 cartridge filter for my pool. It uses 4 standard replaceable filters in a canister. The whole thing is properly plumbed, that is, the intake goes the correct spot, as does the output. The pressure gauge on the top registers pressure in a strange way. Normally when I clean the filter, and replace the cartridges, the pressure runs about 12 PSI on the high power of my pool pump. Now, as the cartridges get clogged, the pressure goes down, not up! Based on that you would think that somehow the pressure gauge stuck on top of the canister would somehow be on the output side, so that when the filters get clogged, the output goes down. I have looked the situation over completely, and the pressure gauge is on the correct side of the equation. That is, the water comes in the inlet from the pump, fills the canister, and is pushed through the filters into the manifold where it is expelled to the pool side. So, I cannot figure out why this is. Now, I have no problem filtering, and all works fine, but what am I missing here???

 

[pooldv]

I don't know what is going on, but those gauges are usually not very reliable. There are some very nice gauges on tftestkits.net fairly cheap if you want to try a new gauge.

 

[dndrich]

I don't know what is going on, but those gauges are usually not very reliable. There are some very nice gauges on tftestkits.net fairly cheap if you want to try a new gauge.

That is an interesting idea. Perhaps I will pick one up when I pick up a new test kit too.

 

[Patrick_B]

If you don't have a good test kit you really should order one. The gauges are nice as well.

 

[jrs_diesel]

Are you purging the air out after you clean the filter? There should be a thumb-screw like fitting at the top so you can purge the air.

 

[dndrich]

Are you purging the air out after you clean the filter? There should be a thumb-screw like fitting at the top so you can purge the air.

Yes, definitely purging the air.

Now, I bought one of the glycerin filled gauges from TFT, and didn't realize that my Jandy CL-580 has a kind of integrated valve system at the top. That is, it has a purge valve as part of the pressure gauge system. So, the gauge I bought I cannot install. Any ideas about how to get a better setup? Or, do I just live with what I have?

 

[JasonLion]

I've never looked at that specific filter. But the parts list shows a standard rear mount gauge. So, the gauge on that filter should be replaceable with any standard rear mount gauge, including the ones from TFT. The purge assembly screws into the filter lid, and the gauge screws into the purge assembly.

 

[dndrich]

I've never looked at that specific filter. But the parts list shows a standard rear mount gauge. So, the gauge on that filter should be replaceable with any standard rear mount gauge, including the ones from TFT. The purge assembly screws into the filter lid, and the gauge screws into the purge assembly.

Hmm. I will have to look it over. Looks integrated, like it might be quite hard to get it out. I bought the wrong one too, since I bought the inferior mount and not rear mount! I will look it over.

- - - Updated - - -

OK, took a better look at it. Should have done that the first time! Looks like the outer retaining ring just pops right off revealing the pressure gauge, which looks like it just unscrews. So, I will get the rear mount and try that.

 

[mas985]

The pump connects to the top port correct?

 

[dndrich]

No. The pump connects to the bottom port and pumps water into the main chamber. It goes through the cartridges, to the interior of the cartridges, then to the manifold and out the upper port. I checked it more than once. The manifold also has a small breather pipe with a screen that I clean here and there.

 

[crabboy]

I've got the Jandy 460 cart filter and i rarely see the pressure go up. I only clean the filters once a year, in the spring after the pollen has
fallen. You have an even larger filter and a slightly smaller pool than I have. You may not see an increase at all with that size filter.

I'm still using the original gauge that came with the filter, it may not be the best, but I like the dial around the gauge where you can set the clean pressure. I've never made it to the dirty line before cleaning it. At most, I think I've seen a 2psi rise over a year.

How long are you waiting from when you clean them to when you think they are clogged?

 

[dndrich]

I've got the Jandy 460 cart filter and i rarely see the pressure go up. I only clean the filters once a year, in the spring after the pollen has
fallen. You have an even larger filter and a slightly smaller pool than I have. You may not see an increase at all with that size filter.

I'm still using the original gauge that came with the filter, it may not be the best, but I like the dial around the gauge where you can set the clean pressure. I've never made it to the dirty line before cleaning it. At most, I think I've seen a 2psi rise over a year.

How long are you waiting from when you clean them to when you think they are clogged?

Well, I usually hose off a few times a year. But this year my pool was pretty green, so I hosed off, shocked, and ran pump full time. Now, pressure was about 14, which is good. But after a few days pressure dropped to about 10, and the pump sounded loud like it was laboring. So, replaced cartridges with new. Again, pressure higher at 14, and pump quiet. So, really weird. This is all before I found this website. I am replacing the gauge hopefully soon. The pump sounds good now and the pool is clean. I will hose off again before starting to heat the pool with solar.

 

[mas985]

But after a few days pressure dropped to about 10, and the pump sounded loud like it was laboring.

That almost sounds like the impeller is getting clogged with debris. Are you vacuuming up a lot of debris? When the pressure drops, have you checked the impeller inlet for debris?

 

[dndrich]

That almost sounds like the impeller is getting clogged with debris. Are you vacuuming up a lot of debris? When the pressure drops, have you checked the impeller inlet for debris?

I know what you mean. But no, there is no debris. Furthermore, when I shocked the pool, killed a bunch of algae, used new filters, after a few days the pump was loud again and pressure down. I hosed down the new filters, which had moderate filtered out stuff, and the pump was nice and quiet. It is still nice and quiet, and the water is clean now. Weird.

 

[jblizzle]

We don't do one time "shocks" If you have algae you are dealing with, you need to follow the ShockLevelAndMAINTAIN Process.

The filter pressure should not drop as it gets dirty.

 

[dndrich]

Right. I did all this before finding this website and method. Fortunately my pool cleared with my somewhat haphazard method anyway and is fine. Got the TF-100 test kit and all seems well. I know the pressure should not drop, but that is the whole conundrum! It seems to do just that! But it can't defy the laws of physics, so something else must be going on.

 

[crabboy]

I have seen my pressure drop in the past right after cleaning them. I'd put them back in, fire up the pump, set the clean dial and then a few days later the needle would be slightly below the clean line. I'd adjust the dial again, and then it is usually good for the year. I don't recall ever seeing a 4psi drop though. I'm still on my original filter media since '07.

I wonder if you had maybe tore one of the filters while cleaning it after your bloom?

What Mark mentioned about the junk in the impeller happens to be all the time. I have to cram my hand into the pump and try to nudge the small _things_ off of the impeller blades. It is a PITA.
Gary