Newbie - question about DE and pressure

[viper99]

Thanks to this forum i have finally decided to manage my own pool. Before that I had a pool guy do the last filter clean.

Here are the particulars

I have a Pentair FNSP 48
We had 4 grids with small tears so I replaced them with a full 8 set

Pool filter area is 48 sq ft

The pool guy said he added 10 lbs of DE (should he have added 5 lbs - i did question him, he said since they are new, more DE is needed. I didnt see him measure could have meant he added 10 - 1 lb coffee cans full which would be 5 lbs) anyway not seeing any DE in the pool so assuming he added 10 coffee cans or 5 lbs

We also had drained and refilled with brand new chemicals and fully clean pool. He put all new chemical and asked me to run the pump for 8 hours.

The pressure started off with 15 psi but after 8 hours now is showing 25 psi.

Should i be worried? The max rated pressure for filter is 50 psi.

Should i add more DE - what should i do?
I am on my own now.
The next time i backwash am i supposed to add 4 lbs or 8 lbs.



Thx
SaGu

 

[PoolStored]

You might have algae, even if you can't see it...causing the pressure rise.

How are you testing your water? Post a full set of results.

Post a full set of pool water test results. Do this test tonight, it will tell you if you have algae. Link-->Overnight Chlorine Loss Test

Backwash and add 4lbs. (Use 4.8lbs for a clean filter.) When pressure rises 25% above clean pressure backwash again.

DE Filter Use and Care - Further Reading

www.troublefreepool.com

 

[viper99]

Like i had mentioned we had drained, acid washed and filled the pool with fresh water so likely was not algae.

On a friends recommendation ended up doing a quick 5 sec backwash and that fixed the issue.

I am happily at 10 psi