pool filter high pressure within 4 hours of backwash

[truss17999]

Hi All:
I am pretty good with my pool but this one has me stumped to the point that I am coming to the forums for help.
I have an 11 yr old inground pool with Triton 2 sand pool filter. I am the original owner. Toward the end of last year my filter pressure was rinsing faster then normal requiring backwashing every couple of days instead of ever couple of weeks. I assumed it was dirty and figured I would deal with it when I opened it this spring.
So yesterday I changed out the sand , backwashed it to get all the sand dust out and yet by this morning again the pressure was high. I backwashed it again and 4 hours later the pressure rises 10 psi which then reduces the pressure to the jets and not enough suction on the skimmer unless I shut the bottom drain.
Let me note that when I do back wash it for a couple of minutes and then a rinse, the pressure does start out normal. Also the pool is clear. I put a heavy shock in it 2 weeks ago when I removed the winter cover followed with a floculant. I ran it on the old sand until yesterday. So that should have left with the old sand.( I would think)

Any ideas?
Thanks
Tom

 

[duraleigh]

Welcome to the forum.

Tom, I think your pool is acting perfectly normal. What you may be missing is that your filter is catching debris that you may not be able to see but it is nevertheless clogging your filter.

I suspect you do not have enough chlorine in your pool.

Can you post a complete set of test results?

 

[pooldv]

Welcome to TFP! Sounds to me like you might have some algae. That was the first sign for me and slightly slimy walls. Post up some test results and we'll see what's up, especially if you have some recent results on chlorine consumption.

Here is some info on updating your signature, What we need to know to answer your questions