Slowly losing suction at skimmer while pressure increases

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C

ckp6844

New member
May 8, 2021
4
NJ
Pool Size
25000
Surface
Fiberglass
Chlorine
Liquid Chlorine
I posted last week about struggling to get a good suction at my skimmers. I originally attributed it with junking up the filter with a phosphate remover, however, even after clearing that out, I still lose suction after about a half hour of use. Very frustrating because I need to get a good vacuum in! I’m hoping to resolve this with a little DIY without involving my pool guy.

My two concerns are the low suction with a high pressure reading. When the system initially starts up, pressure is about 23 psi, and then it slowly creeps up and levels around 29. That's when I see my skimmers are basically useless.

I’m thinking (with my pretty limited knowledge) I may have two problems going on since I can’t find any articles or posts about the two being related. Usually it’s the opposite relationship, no?

Here’s what I’ve done so far
- backwash, remove and rinse filter
- recharged with DE
- lubricate o ring at pump
- checked impeller and pump for obstructions

My observation
- slight drip on suction side while system is both on and off. Looks to be around the Hayward Cyclolac ball valve. I’ve attempted to tighten this but to no avail. Should I try lubricating this? Glue? Or is that a waste of time?

The pool guy explained that would be impossible because only air leaks can occur on the suction side while on, and it shouldn’t be contributing to this problem. He hasn’t seen the problem himself because when the system starts up, it primes and runs perfect (wish he would stick around for a bit and watch!) I also considered that a grid could be damaged, but I think I can rule that out. Pool guy had the thing disassembled and cleaned and I assume (hopefully) he would have caught that.

I can provide photos or more info about my equipment if necessary. Thanks!
 
"ckp" what you are describing is reminiscent of an algae problem. It may not look green, but the water can be overloaded with organic material before it goes green. You do a backwash and it's fine for about 20-30 min before it shoots up again. Classic algae. To be sure, please post a full set of water test results from your TF-100 or Taylor K-2006C test kit. Also be sure to update your signature with your pool and equipment info. You can also do an Overnight Chlorine Loss Test to see if there is an excessive FC demand which confirms algae. If you have questions just let us know.
 
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Thanks for your quick reply. I'm new here and finally weaning off relying on the pool store. Taylor K-2006C was ordered yesterday and should be here Sunday. I'll provide my in-store analysis from 5/12 below, but I know those readings can be bogus. I'll follow up once I can test with my home kit.

pH 7.7
Alk 121
CyA 27
FAC 0.7
TAC 0.8

I since shocked with a gallon of liquid chlorine (12.5% sodium hypochlorite) but pending new reading. I should also mention this is a fresh-filled pool on 5/4. My mind was focusing on a plumbing issue rather than a water issue. I'm glad I asked.
 
Glad to see you have K-200C on its way. :goodjob: Until the kit arrives, I would add 1.5 gallons of 10% chlorine now (about 6 ppm), then plan on adding about 1/2 - 3/4 gallon each day thereafter until the kit arrives. A lot can happen in a week since you filled, so I'm sure the water needs chlorine right away. Hopefully your water is chilly which helps to slow down organic growth.
 
ckp,

Your filter pressure is really a measurement of the amount of effort that it takes for the pump to push the water through the filter and then back to the pool.

High pressure indicates that "something" is between the pump and the pool.. As Pat has pointed out, something is most likely clogging your filter. Most likely algae, but it could be plaster dust or some other chemical in your water.. The key here is that the pressure is increasing.. High pressure that does not increase generally indicates a plumbing issue or a valve setting problem.. Increasing pressure over time almost always indicates a dirty filter.

Thanks,

Jim R.
 
Figured I should follow up in hopes that this helps someone else in the future.

Yep... just needs frequent backwashing. This year we opened about 3 weeks earlier than usual and I didn't realize how bad the pollen is at this point. I reintroduced skimmer socks and it gathers a crazy amount of gunk in just a few hours. Photo below is just from 4 hours this morning. Clean filter pressure is 18psi and I backwash near 30 or when suction diminishes.

I'm new to the TFP method so I'm still getting used to recommended levels. I'm trying to keep my chlorine high to avoid algae.
FC 7.5
CC 0.5
CyA 30
pH 7.2
TA 125

Thanks again for the help!
 

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ckp, early on we were concerned about algae. Your numbers seem to be good right now, and your skimmer sock is doing a nice job grabbing surface junk. But watch things closely. Now that you are able to test FC accurately, be sure there is no excessive FC loss in a 24 hr period. If there is (more than 4 ppm), or if you see cloudiness or green in the water, it's time to follow the SLAM Process. We also offer the Overnight Chlorine Loss Test as a test to rule-out algae as well. Different tools available. If you have a question, let us know.
 
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