Broken suction side pipe causing high filter pressure?

[xing68]

Hi,
I have an DE filter, it worked perfectly all Summer, but now the weather getting cooler I am having issue with it.

At the beginning of the month, I noticed the filter pressure was high, the normal pressure is about 19, it reached 25. so I did a backwash and the pressure was back down to 19. But within one week, it gone up to 25 again. I want to say my pool is clear, so I don't think there is that much algae. And I did backwash again, but within one week, it went up to around 30. So I took off the filter and clean the cartridge, there were some hard stuff looks like sand or dirt. After the cleaning. the pressure went back to 19, but after one week, it shoots up to 25 again. I did another backwash today, and within couple of hours, the pressure is already at 21.

So my questions is, does this sounds like something was sucked into the filter constantly? maybe some part of the suction side pipe is broken, so it sucked in the sand and dirt?

I have two things support this:
1, I found 2 pieces of rusting screw in the pump strainer. I don't think stuff that big can pass through the skimmer to reach the strainer. so it has to get in from broken pipe.
2, As I said, when I cleaning the filter, I see something look like sand or dirt.

But the thing puzzled me is, I did not notice any significant water lose. If the pipe is broken and stuff like screw can get in, it must be a big hole and we should see noticeable water lose, right?

That's why I come here for advice before I spend that money for leak detection company.

Any comments is much appreciated.

Thanks
xing68

 

[Mike1162]

What's the brand & model number of the filter? A leak on the suction side would allow air into the pump that you would be seeing through the lid. You may need to do a chemical clean on your filter's grids/cartridges.

Algae will quickly clog a DE filter. Do you know your CYA & free chlorine levels?

 

[Jimrahbe]

68,

99% of the time, when filter pressure goes up, and can be reduced by backwashing, and then it goes up again, it is algae.

You can have algae that will clog a filter in a week and not have green water.

Algae is always a chemical issue, so we need to know the following levels..

FC
CC
pH
TA
CH
CYA..
Salt, if a saltwater pool.

Thanks,

Jim R.

 

[wireform]

What Jim said but more so with DE.

 

[xing68]

Thanks for the advise, my filter model is a Jandy DEL60
I will test my water chemical level, and do a chemical clean on my filter's grids/cartridges. I never did that but I can google it.
Another thing is those all happens after I got a new brand of DE, will bad DE clog the filter grids?

Thanks
xing68

 

[Jimrahbe]

68,

There is no such thing as "bad" DE.. As long as the DE is made for swimming pools it will be just fine.

Chemically cleaning your grids will just be a waste of time if you have algae, as I suspect.

I assume that you use chlorine tablets to sanitize your pool water.. My guess is that your CYA is way over 100 ppm and that your Free Chlorine Level (FC) is less than 1.0 ppm.

Thanks,

Jim R.

 

[xing68]

Jim, yes I use tablets, I will test my water tomorrow and let you know.
Thanks
Hongfei

 

[xing68]

looks like CYA is 0 and PH are too low?

 

[wireform]

Hongfei,
You're just wasting your effort with those strips which we can't advise you on how to treat the pool. You need a real test kit such as TF-100 but more importantly read test kits compared.

 

[Jimrahbe]

Hongfei,

Unless you just replaced all your water, what your test strips show is just about impossible...

I don't like pool store testing, but it is better than nothing.. Go get your water tested and let's see what they show.

Thanks,

Jim R.

 

[xing68]

fighting the flu today, but managed to get water tested at pool store. Please see below. The guy at store told me I need to first increase the PH value and then shock the pool. So I bought some Soda ash and plan to add them when I am feeling better.
Please take a look to see if anything else I need to do?
Thanks