Intex metal frame pool pump flow loss within 24 hours of filter change

[pendragn32]

Greetings. I have been watching these forums and learning for the 7 years I've owned an Intex pool, but this is my first time posting. I purchased a replacement Intex pool last season (12" by 30" metal frame), so my pump is about 15 months old. In the 7 years I've had an Intex pool, I've never experienced this issue. Here's what's happening:

I have 4 Unicel 4607 reuseable filters that I have purchased one at a time for the last 4 years. When I started up the pool this year, everything was fine. But for the past 2 weeks, after I replace the filter, the pump's flow reduces to almost 0 within 24 hours. When I first replace the filter, the flow is normal. But then it steadily declines until it's almost non-existent the next day. If I take the filter out and put another one in, the flow returns to normal, and then drops down to almost nothing by the next day. When I clean the filter after one day's use, it already "looks" pretty clean to begin with- certainly not dirty enough that I would think it would reduce the flow. Yet replacing the filter with a clean one returns the flow to normal for a bit. It's happening with all 4 filters.

I can't figure out what the issue is. The water looks clear, the pH balance is normal (it drops down to 7.3 or so within a week, just as it always has every year, and I bring it back up to 7.6), and the chlorine level is steady between 2 and 3. I don't know if there is an invisible containment that's blocking flow, or if there is something wrong with the pump itself (which again seems normal with a fresh filter), or if there is a suction issue. I did notice a bit of cloudiness in the water and a bit of slipperiness on the pool bottom around when the issue first occurred, but I went all in on superchlorinating and the water looks/feels better now. But maybe I didn't get rid of something.

With everyone and their grandma buying backyard pools this year, the normally $25 filter pump assembly is now going for about $75 used and I just lost my job, so I'm hoping the issue isn't the pump. But I'd really like to get this fixed.

Thanks in advance for your help!
-Doug

 

[mknauss]

Welcome to the forum!
The majority of the time, what you describe is algae in the pool water.
How are you testing? Can you provide a full set of test results from your own kit?
At your pool size, you could treat this as a Seasonal Pools. In that case, you drain, clean, refill, and start over when your water gets cloudy or has visible algae.
I suggest you read ABC's of Pool Water Chemistry.

 

[pendragn32]

Thank you very much for your help! I hadn't seen the Seasonal Pools guide before, and that is quite helpful. I use the HTH 6 way test kit, and most weeks I just test Chlorine and pH after initially getting Alkalinity to where I want it. I tested this afternoon, and the chlorine level had actually dropped to 1, so it's definitely getting eaten up more quickly than it should. I use three 1" tablets at all times and Shock XtraBlue weekly and after each swim, and that usually keeps the level closer to 3. pH was 7.3, Alkalinity at 110, and I stopped counting CH at 260. Taking your advice, I'm currently draining the pool. I scrubbed it down, and I'll scrub it again after the water is fully out and start over from scratch. Hopefully that takes care of it.
Thanks,
Doug

 

[mknauss]

Great. Just remember, continuous use of solid chlorine products (tablets and shock) are not recommended.

 

[pendragn32]

I've been going for years based on another post I had seen on this forum for Intex pools, so the Seasonal Pools information is new to me. So just to confirm, you're recommending I just go with the unscented household bleach daily rather than tablets and shock?

 

[mknauss]

Once you have used enough dichlor or trichlor to get to 30-40 ppm CYA, you then go with liquid chlorine.

Be sure to fully read the article.

 

[pendragn32]

OK, I will make the switch to the liquid chlorine. I did read through the article.
I filled the pool up again yesterday afternoon, and as of right now, the pump is still going strong. So you were absolutely correct in your assessment of the problem. Thank you again for your help!
-Doug

 

[chipchip]

You should have no need to shock the pool if you keep your chlorine level where it should be. You have to allow for the level to drop off every day in the summer heat so if you only bring the level up to its bare minimum it will fall below every day before you put more chlorine in, and that will allow algae to grow. To combat that I raise it above where I want it every night and so it never falls below. Also, in my area, it's cheaper right now to buy pool chlorine than it is to buy bleach at the grocery store (there is no difference except for the strength, bleach is usually around 7 or less, and pool chlorine is 10 but they are the same thing otherwise as long as you don't get splashes or some kind of scented).