Filter Pressure Help

[jeeper41]

I have in in-ground pool that i am having some difficulty with. I suspect there might be a hole in the return lines. The pool is set up like follows: 2 skimmers on one line into filter. 2 return lines come out of filter one to step returns and one to main returns. I just backwashed the filter (DE) and the pressure has come down to the normal 12 psi when I have the main returns on BUT the pressure is up at 20psi when I turn the step returns on. I need to use the step returns as there is a hole in the main return lines. Why would the pressure be so hi on the step returns?

Would a clog in the return line cause hight perssure in the filter?

Please help. My kids want to go it.

 

[Bama Rambler]

Are both lines going to the returns the same size?

What size eyeball is in the step return?

A clogged line will cause it, but a small eyeball in the return will do the same thing.

Are the ruturn lines approximately the same length?

If the main return line has a leak that would lower the pressure in that line.

 

[jeeper41]

Are both lines going to the returns the same size?

What size eyeball is in the step return?

A clogged line will cause it, but a small eyeball in the return will do the same thing.

Are the ruturn lines approximately the same length?

If the main return line has a leak that would lower the pressure in that line.

Yes they are the same size.

My guess is a 1/2 inch eyeball. It is the same size as the main returns.

The returns are about the same length

Although the main line is leaking. the pressure is the same as it usually is. The step returns used to be about 12 psi and is now 22psi.

 

[Bama Rambler]

Although the main line is leaking. the pressure is the same as it usually is. The step returns used to be about 12 psi and is now 22psi.

The plot thickens!

Remove the step eyeball and see if the pressure goes down. It is leading to the return line being plugged. Hopefully it'll be right at the eyeball and will blow out as soon as you remove it.