Low Pressure on Pentair CC100 Cartridge filter

[bobodaclown]

Hello all.
Replaced bad PSI gauge. Installed new gauge. It's reading 8 psi then added 2 large cups of synthetic DE and didn't get a psi increase. I'm getting good flows from the return ports. I'll know more tomorrow when I look at the pool and get new readings.

The pump is 1hp Dura glass any ideas what may be wrong?

 

[duraleigh]

You have something obstructing or restricting the suction side of your system or a suction side air leak.

What is the normal psi? Is the pump strainer basket full of water when the pump is running or does it have air in it.

 

[susa]

Just to show that a low psi is not necessarily a trouble ticket... am running a CC200 and it shows barely 2 psi when system starts initially and drops to zero once optimum run speed has been achieved at the programmed RPM and GPM rates. There is nothing wrong with my system running at Zero Psi as the IntelliFlow VF maintains automatically required flow rate.

 

[duraleigh]

There is nothing wrong with my system running at Zero Psi

Well, a variable speed pump (which OP does not have) can certainly run lower but it seems to me that, from a technical standpoint, zero psi would mean zero flow of water, too.

I think for the pump to push the water into the pool, it has to overcome the resistance of the system. It does that by building pressure.....perhaps very low but pressure, nonetheless.

 

[susa]

>> I think for the pump to push the water into the pool, it has to overcome the resistance ..

it does that initially upon startup (2 psi) and once flowrate has been achieved, the programming drops RPM to below 1000 / watts to ~100 and psi drops to zero

oh and just to show this is not an anomaly, I can set GPM to 45 or higher and get psi needle up to 20

 

[Bama Rambler]

Not to carry this thread farther off topic (because none of this is helping the OP) but if it was truly zero then you'd have zero flow. It's just not enough that your gauge can read.

bobodaclown -- Please forgive the side step of this thread. Now back on topic.

There may not be anything wrong. Adding DE will usually add some pressure to the system but then again it may not add enough to change the gauge. Watch it for a few days and see if the pressure rises from cleaning the water better.

I can add DE to my sand filter and the pressure gauge never moves more than 1/2 a psig no matter how much I add. And I have a calibrated gauge.

In essence, unless something else is going on, don't worry about it.

 

[bobodaclown]

Hello,
Just an update.
PH= 7.5
FC=11
CC=0
TC=11
CYA=100+
Pool is looking good. Overall. Working on my run times. My filter did climb to 10 PSI up from 8 PSI. I've got another filter on order. I'll replace the old one when the new one comes in. I looked at the old filter today. Looked in ok shape, not sure really what to compare it to. I'll wash, degrease, then rinse and dry and be able to swap out filters.

 

[Bama Rambler]

I would probably start working on bringing that CYA down now. Even if you do it slowly you'll be better off in the long run.

 

[bobodaclown]

WOW! It's been hetic around here. Moving and the such. My CYA was way High. I did a dilution of 50/50 pool and tap and it was still above 100 when I tested it. I tried using the pool pump to drain, well, that really didn't work too well. Only drain is the air drain on the top of the filter it's 5/8 inch. Soooooo.. To Homedepot I went. Picked up a little sump pump. Much faster...
Drained about 3 feet of water from the pool.
I was doing the pump and add at the same time. Wasn't going so well. (another story). So drained to the bottom step or so. Then added water. Tested the CYA and its right around 100. I need to get it down to 80 (adding a SWCG).
Oh.. added a new filter and I get 2.5 PSI.

Also new numbers from fill: 5/17/11
FC=5.5
CC=0
TC=5.5
PH=7.7
TA=170
CH=225
CYA=100

I added a 182 oz bleach to bring up the FC to 11 ish.

 

[JasonLion]

Good progress