Experiencing Low flow rate with pool


New member
May 11, 2015
Austin, TX
Within the last couple weeks I've notice the flow rate has significantly gone down. I have a variable speed motor and noticed the suction vacuum no longer moves, as well the flow to jets and bubbler is decreased quite a bit. In the past, it's been a matter of cleaning the filters and everything works fine. Now that's not that's not the case. I cleaned the filters yesterday (let them soak with tablet cleaners for an hour) and started up the pump. Everything worked great for about an hour or so, but then noticed flow rate decreased again???

I checked the impeller for blockages but can't find any, and don't appear it see any air leaks on the suction side...my pool is only two years old. Can my filters be bad already ???

Is there a way to determine i need new filters before I pay a pool company to diagnose??

Thanks in advance for the help


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

Welcome to TFP.. A Great resource for pool owners with flow issues... :shark:

What you describe is pretty typical when a pool has algae whether you can see it or not. I really doubt that your cartridges are bad. Algae can quickly clog any filter.

I noticed you said that in the past you just cleaned you cartridges to solve the issue.. Well I have the same basic filter and I can go a year between cleanings and I have a bigger pool. Why do you think that is?

Is your water clear or a little cloudy?

How are you currently chlorinating your Pool?

This website is all about the pool owner taking control of there own pool water testing so that they know exactly what needs to be added, or more importantly, what does not need to be added to their pools.

Can you provide us with the following readings?


Without that information it is pretty hard for anyone here to accurately diagnose your pool's problems.

You might want to review our Pool School (Link a the top of this page). You can start with this overview... Pool School - What is TFPC?

Thanks for posting,

Jim R.


New member
May 11, 2015
Austin, TX
Thanks for the detailed reply Jim. My water is currently cloudy in appearance. I had no idea that algae can clog filters that quickly. I guess I thought cleaning filters every month during swim season was a typical thing, and I've had algae come up before and it's never reduced the flow this much...guess that's where my concern came from...I have a tablet feeder, and use liquid chlorine when needed. Last year I purchased a solar ionizer, which adds small dose of copper to water to kill algae. It worked awesome last year, I was having algae issues off and on, but the ionizer seemed to clear the water perfectly all last year even when chlorine was low. (that's the idea behind it)

I had the water tested at a local swim shop and the results are below. My FC and CC were low (guessing cause the present of algae) and I was recommended a super shock package, cleaning filters with product, and replacing some water to reduce the CYA.

The readings from the store were:

FC Low
CC Low
CH 220
CYA 85
TA 80
pH 7.5

After this I cleaned filters, replaced maybe 10% of water, and added one bag of super shock to pool. As I mentioned before, right after cleaning filters the flow was normal (how things were when it was first built) but after an hour (maybe two) I noticed the flow had gone down again.

Checked the readings the next morning and noticed the chlorine level was low again (pH was around 7.6 and TA around 90) so I added 64 oz of liquid chlorine and confirmed it was above 5 about an hour later. Just checked it at the end of the day now and low again??? I cleaned out the tablet feeder and checked for blockages, but it seems as though it's not working effectively...sorry too many variables