Cartridge Filter only last 16 months?

Twolabs

LifeTime Supporter
Apr 13, 2014
329
NE Texas
#1
We finished our pool in November of 2014. Since we are in Texas, we leave it open year round.

Have a 3hp Tristar Hayward pool pump as the main pump, and a 525 sq ft cartridge filter. I stay on top of the chemistry and haven't had any chemistry related problems as of yet.

I cleaned it not long after the pool was finished because of all the plaster dust. The PSI came immediately back down to the brand new level (right about 20 PSI). The pool builder put the red line indicator on the PSI gauge at 30 PSI. I cleaned it again sometime last year when it was approaching the red line and the PSI gauge came down, but not all the way. It stopped right about 22-23PSI.

Just recently, I noticed that the pool heater wouldn't stay on. You could hear it trying to fire, and then it would go out. I texted my PB and he said that the filter is probably dirty (I hadn't checked because I didn't think it would be time to clean it again). Sure enough, it was borderline 29-30. So I took it off today and they were pretty dark and dirty. So I cleaned them very good, took a long time and got just about every speck of debris out. They don't get as bright white as they used to (some brown stains here and there), but this was a big difference between the before and after.

I put it all back together, expecting the PSI to come back down...but it came down maybe 2 PSI. Its' reading about 28.5. :confused:

I turned on the heater, and this time it worked and stayed on. But I also noticed that when the heater is on, the PSI jumps to almost 40 PSI.

I came inside to order some new filters, but just can't believe they would only last 16 months.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#2
Your filters should last much longer. Typically we clean our filters when the PSI increase by about 25% from the baseline (clean) pressure.. But now you seem to have another problem. Increased pressure, even after cleaning the filters, may point to something else upstream increasing resistance. Still, to be safe, it may help if you can give us a full set of test results from your TF-100 or Taylor K-2006. Sometimes the tests clue us in on something else to be extra vigilant about related to your issue. I don't own a heater (South Texas) :), but perhaps a heater expert will have a heater-specific diagnosis for you as well. More to follow.

PS - Beautiful set-up you have there. Amazing stone work. Wow.
 

Twolabs

LifeTime Supporter
Apr 13, 2014
329
NE Texas
#5
So I did the TSP soak overnight, washed it off, put it back together and it made zero difference. Not even a half PSI.

So now, should I just go ahead and order new ones and then if THAT doesn't change we have a more serious problem?
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,976
DFW, TX
#8
If you order some new filters get some Pleatcos. Pleatcos work much better in my filter.
 

Twolabs

LifeTime Supporter
Apr 13, 2014
329
NE Texas
#9
Well I went ahead and ordered some because I know I'll need some anyway at some point, even if I get this issue figured out (too late Pooldv, I ordered Unicel, I went back and forth and read good and bad things about the Pleatcos, I'll try that next time).

Here are my results, they were a little out of whack I guess coming into the warmer months I let some things slip by me.

pH 8.0 (added some MA)
FC 2.0 (added some bleach)
CC 0.0
CH 175 (added some calcium)
TA 80
CYA 20 (adding some stabilizer)

Pool water is crystal clear and has been.

Any other ideas as to why my filters only lasted so short amount of time?

By the way, my PSI when they were brand new was at 20. They climbed up to 30 when I washed them off this time and only went down to about 28.5. After the TSP soak, they stayed right at 28.5.

The only other thing I can think of is we have a lot of really pretty verbena growing on one side of the pool and some of them were dipping down into the water (just about 5 or so buds worth). I've cut them back now, but could that be something so small that it clogs up the filters but won't wash out?
 

Twolabs

LifeTime Supporter
Apr 13, 2014
329
NE Texas
#13
It's not, generally, but you're troubleshooting, It's no different than jumpering some kind of safety switch during diagnosis.
Okay, so just essentially take everything out (including the top plastic portion that snaps onto the cartridges and the outflow pipe?) and fire it up for just a few seconds to see the PSI, then shut it down?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,322
San Dimas, CA (LA County)
#14
Okay, so just essentially take everything out (including the top plastic portion that snaps onto the cartridges and the outflow pipe?) and fire it up for just a few seconds to see the PSI, then shut it down?
I'm not familiar with the internals. But whatever it takes to eliminate the paper cartridge while still being watertight.
 

rphpool

Well-known member
Mar 4, 2015
454
Sugar Land , TX
#15
Just grasping at straws here but when I clean my filters I close the suction valves to keep water from flowing back. Is it posible a return valve was shut off or partially closed by mistake?
 

Twolabs

LifeTime Supporter
Apr 13, 2014
329
NE Texas
#17
Just grasping at straws here but when I clean my filters I close the suction valves to keep water from flowing back. Is it posible a return valve was shut off or partially closed by mistake?
I don't close any valves when I clean the filter. Perhaps I should? All I do is release the air pressure at the top, drain the entire filter container, and then open it up.

When your cartridges are in the filter and you are showing 29-30 psi, what rpm is that big pump running?
I have no clue. Its a one speed pump. I wouldn't even know how to go about finding out?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#18
Twolabs, the only other thing I would add to this discussion now that you have added your test results is chemistry. Once you've checked all the mechanical items that everyone else has suggested, if it doesn't seem to work, go back to basics - chemistry. I say that only because your CYA and FC were quite low. If they were that way for very long, your water may look clear but still be clogging-up the filter with organics. You might want to consider doing an OLT "IF" the other suggestions don't work. Just a thought. Doesn't really cost anything to do, and who knows?..... might show us something. You wouldn't be the first lately who had clear water clogging-up the filter only to find out it was algae in its early stages. Best of luck to you either way.
 

buzzard302

Well-known member
Jun 6, 2013
124
South Florida
#19
Dumb question, did you tap your pressure gauge a little bit? My old pressure gauge can stick up high sometimes, and a quick tap on it settles it back down. Some day, I'll grab a better quality pressure gauge.
 

Twolabs

LifeTime Supporter
Apr 13, 2014
329
NE Texas
#20
First of all, thank you for all the help so far. This is such a great resource of information!

Alright, I think we can rule out the cartridges (as others have suggested). So I guess I'll put the replacement cartridges in storage.

I took out all 4 cartridges and ran the pump, zero change in PSI. Still sitting right around 28-29 PSI (20 PSI brand new). All main drains look clear. All returns look clear. So this means something in a pipe or in the heater?

Thanks again for the help thus far.