Question after cleaning 60 DE filter for first time

Chad_in_TX

Member
Jul 24, 2019
15
Plano, TX
So new equipment and plaster has been running since mid June. At the end of June, and at the end of the plaster care, they cleaned the filter. However, just after a short period of time, I’ve already had to open it up and clean it. This is the Quad 60 DE cartidge filter, without backwash. When I had this installed, the rep said I would only need to clean this a few times per year. I was a bit surprised, when my PSI already spiked after just a short period of time...

Is this normal due to the new plaster (just standard white)?

My pool doesn’t have a lot of direct leaves, but lots of small particles and dirt are always flying into the pool due to surrounding neighbors with huge trees....

Within the last couple weeks, I started using a sock filter on the skimmer and I brush and skim the pool religiously and run the Polaris daily, so their isn’t a lot of debri left in the pool.

After I cleaned it, it’s currently at 20 psi. Is that sounding about right?

Should I basically just expect to clean it WAY more often than the “couple times per year” that I was sold on?
 

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Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,633
Bedford, TX
Chad,

I have two pools with DE filter... both about the size of yours.. one has a 60 Sq ft filter and the other a 48 Sq ft filter... I clean both of those filters twice a year. These are rent houses, so I don't use hairnets in the skimmers..

To me, that means something is wrong. Both of those pools have VS pumps that run slow, so that helps a lot, as my filter pressure is usually about 5 lbs.

What we really need to know is.. "What is your clean pressure?" And what is your current pressure, and how long did it take to get there???

Since your filter has already been cleaned of any plaster dust, the first thing that crosses my mind is an algae bloom, even if you can't see it..

Have you run an OCLT???... Overnight Chlorine Loss Test

Please post a set of numbers...

FC
CC
pH
TA
CH
CYA

Thanks,

Jim R.
 

Chad_in_TX

Member
Jul 24, 2019
15
Plano, TX
Here is my current stats as of this morning:

FC: 7.0
CC: 0
PH: 7.4
TA: 70
CH: 260
CYA: 50

PSI: stayed at 20 overnight

My biggest concern is why would my pressure have only gone down to 20 and this was only the 2nd time cleaning them...I didn’t use just a hose, I spent over an hour on the 4 cartridges cleaning them with a pressure washer... my thought process is if I can only get down to 20psi as my starting point, it’s only going to get worse going forward....

Is there a chance the pool tech the first time didn’t charge the filters with DE and it’s ruined them? The pool company is reluctant to be coming out and they are going to try and pass the buck off to me, which I clean this pool twice a day and maintain the chemicals pretty good. I just don’t see how this is happening.


And I’m not even sure what CSI is. This is the first I’m hearing about it...
 

JamesW

TFP Expert
Mar 2, 2011
16,595
What is the model number of the pump?

CSI is the measure of saturation of calcium carbonate.

New plaster gives off calcium hydroxide, which becomes calcium carbonate.

Calcium hydroxide raises a pH and can cause scale.

Your pH might have gone high for a while causing scale.

Do you have scale on anything?

You can track CSI using PoolMath.

Do you have a picture of the system?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,633
Bedford, TX
Chad,

What else changed in the system since you remember a filter pressure of 11 PSI?

If everything else is the same, it has to be the cartridges... Anything in the return path will increase your pressure... Eyeball sizes, valves not fully open, etc.

20 lbs is not all that bad... As long as you have good flow back to the pool, there is no reason to not live with it the way it is...

Are you sure you did not add way too much DE??

Thanks,

Jim R.
 

Chad_in_TX

Member
Jul 24, 2019
15
Plano, TX
When they turned on the pump after the plaster was done, I remember the pressure was at around 11 or 12. Two weeks later when they were done with the pool care, they took out the cartridge to clean it (I didn’t actually watch him do it or look to see how much DE they put it, if at all...) but when they left they turned the dial to the starting point of 25. When I cleaned the filter yesterday, it was reading 34. It didn’t dawn on me I should have questioned why it was so high after they cleaned it for only the first time, until it took me so long to clean it last night and then it only went back down to 20...

I’ve tracked my chemicals on my app since they started the pool and the only thing that’s ever been not balanced was some low chlorine levels for a bit early on, but those got under control. PH was always in the ideal range...

I guess my thinking is if the best starting point I can get is 20psi now, won’t it just continue to get worse as the filters age?
 

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Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
14,633
Bedford, TX
Chad,

If this were my pool, the first thing I would check is the return flow back to the pool at the eyeballs... If the flow as good, I would use 20 as your new clean pressure, for now.

My thought is what other options do you have? The only one that makes sense is to replace the cartridges and see what you get. A great idea, if the pressure drops to 11 PSI... a pretty expensive idea, if it stays at 20. The other thing I would do is to actually weight the DE you are putting in the first time. Don't just assume that the scoop you are using is a lb. or 1/2 a lb.

In theory your cartridges should not should no go bad over such a short period of time. Logic says that either the cartridges were damaged somehow or they were not. I would not think that a little plaster dust would cause them to go bad.

Again.. if the flow back to the pool is good and strong, I can't see any reason to worry about it..

That said, if this were my pool I would install a new set of cartridges.. If it fixed the problem, great.. If not, I would use them as spares and swap out at cleaning time.

I am not sure that your cartridges" aging" comment is true... :scratch: My cartridges are five years old and appear to me to work exactly like they did when they were new.. They are no longer white, but other than that I can see no difference in operation

Thanks,

Jim R.