High Filter Pressure, Low Flow, Minimal Suction

briansturgeon

0
LifeTime Supporter
Feb 22, 2011
109
Cincinnati, Ohio
Just opened pool today. Problem is that I have cleaned filters three times already and each time I run the pump the pressure goes sky high in less than 10 minutes. After cleaning this last time it never went down. I just sprayed them with a nozzle on the hose. I had a company close pool last year and they took filters with them and acid washed them. I do have alot of algae I'm trying to clear but to me it should still take a little while to get the cartridges dirty before pressure shoots up.

Does high filter pressure create minimal suction at the skimmers and create low flow so that the swg would not even work if i wanted it to right now?

Could a suction side leak at the pump cause this?

What else should I look for?

Thanks.
 
If you have a lot of algae, the filter will clog quickly ... that is what they are designed for. Yes this will lower the flow rate and suction from the skimmer and may not be enough to keep the SWG on ... but we generally recommend not using the SWG when performing the shock process (You are doing this right??? Exactly how it is described in Pool Shool???)

suction side leak can result in lower pressure, not higher pressure. Is there air in the pump?
 
Just turned pump on after spraying off filters. Running at 2150 rpm at 22 psi and won 't even keep running. It kicks out. The flow red light is on the intellichlor but I'm not trying to use it anyway because I am following PoolSchool shocking instructions. Just kinda hard with no pumping/filtering going on.

Can I run without my cartridges in to make sure there is nothing else going on?

There is a little air in pump but nothing out of the ordinary. I know ideally there is none. I may need a new oring for one freeze plug but I just wanted to make sure that wasn't creating all pressure issues. I didn't think it could.
 
Another struggle due to the dumb SVRS pump ... seen a lot of these recently.
Also, not uncommon to see an air bubbling in the top of the pump when running on lower speeds.

Yes you can try running without the cartridge to see if that is causing the flow restriction.
 
Until you get it fixed you can also run in recirculation. This won't filter (obviously) but will still provide the mixing that will help with the shock process. At this point this is probably more important anyway. If pressure is still high in recirculation then you know you have a blockage - somewhere on the pressure side of the pump.

Remember from pump curves that flow rate is inversely proportional to pressure (not 1:1 though).
 
aomagman78 said:
Until you get it fixed you can also run in recirculation. This won't filter (obviously) but will still provide the mixing that will help with the shock process. At this point this is probably more important anyway. If pressure is still high in recirculation then you know you have a blockage - somewhere on the pressure side of the pump.

Remember from pump curves that flow rate is inversely proportional to pressure (not 1:1 though).

Most all cartridge filters do not have multi-port valves with a recirculation setting.
 
I tried it without cartridges and it runs fine. Almost 0 psi when at 2150 rpms and only like 4 or so at almost 3000 rpm. No air in pump either.

Put them back in and once again pressure problem.

I have no re-circulate.

How can I continue on the shock process with no filter. Will it harm the filter or anything else to run with no cartridges to at least get all algae exposed to chlorine and killed at this point?

Then I can filter everything once dead?
 
New Cartridges and Dead Algae

Merged by moderator. Please keep your related topics together. Thanks, jblizzle

Still going through the shock process. Will probably be finished with it after today as my numbers from last night and this morning looked almost good to go. My problem is that I've been running the pump mainly without filters because my filters caused the pressure to be too high. Therefore I bought a new Unicel set yesterday that should arrive tomorrow. I had a lot of algae in the pool after opening and it is all dead now but i'm leary of sticking this brand new set of filters in there to get it out. I don't want to ruin them. Do you think they will be okay if I make sure to wash them several times?

My original ones only last two seasons. I want to make sure to get much more use out of this set. I soaked my current ones overnight in acid then washed. When I put back in my psi was still higher than it should have been. I could only run filter about 2 hours before getting too high of psi therefore I pulled them again. Trying to limp through this and finish cleaning with old cartridges to save the new but don't know if it will get it done or not.
 

Enjoying this content?

Support TFP with a donation.

Give Support
After you acid washed, what was the initial pressure? How high did it rise in 2 hours?

If you are clearing up algae ... this sounds completely normal to have to clean them a LOT ... the downside of a cartridge filter when you get algae.

Using the new cartridge will not hurt them ... this is what they are designed for. Just make sure you clean them when the pressure goes up 25%.
 
Pool running at 2100 rpm after cleaning at 8 psi. Went up to over 20 within two hours and the low flow light came on the Intellichlor (not using during shocking I just use that as my indication that my flow is too low to be doing much) and suction at skimmers was not good nor return flow from returns.

My cartridges don't look anywhere near as bad as some others I've seen pics of. Just gray. Only thing that confuses me is that when I sprayed them off after pulling again I didn't really see nasty water coming off them so I don't know why psi climbed so high. Maybe dead algae is hard to see on the filters when washing off????????????

I will try to put them back in after work and see what psi i get. Then I'll decide about using the new carts or not.
 
So the acid wash seems to make a huge improvement in the initial clean pressure right?

Again, sounds like you just have a lot of stuff in the water that the filter is catching.

I am guessing you would see the same kind of rapid pressure rise if you use the new cartridges as well.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.