Whatt is considered a "normal" operating range for the filter pressure gauge?

[aerangis]

I have a 35k gallon in-ground pool (40x20 rectangular) with a Jandy DEL 60 Filter. The pool is 5 years old and when first built the pressure averaged 16-18 pounds of pressure. Now, despite having thoroughly cleaned the filter elements, the pressure averages 22-25 pounds of pressure.

I was told by the builder that any time the pressure gets up to 20 pounds or more that the filter needs to be cleaned because it's dirty. I've cleaned the filter 'till I'm blue in the face to no avail, any suggestions?

[PoolDoc]

I'd have to see what's downstream of the filter, to get an idea. I'd also need to know the make and model of your pump. You also need to check your gauge, and see if it's going to zero when it's off. If not, get a new gauge like this one:

Super Pro Pool Filter 0-60 Pressure Gauge 1/4" Fitting @ Amazon (http://www.amazon.com/exec/obidos/ASIN/B002JK6I28/poolbooks) You'll need some pipe dope or a roll of Teflon tape to install it.

The BEST way to supply some of this info, is to send pictures to poolforum@gmail.com, and let me post them.

But . . . 25 psi is too high for sustained operation on most filters. It's possible for DE membranes to get contaminated with lotion and oils that can be nearly impossible to remove.

[aerangis]

I replaced the pressure gauge several weeks ago so I assume that factor can be removed from the equation. Regarding the pump, it's a Jandy Stealth 60 2 h.p.

[PoolDoc]

I looked up the Stealth flow curves -- you're definitely pushing the boundaries of allowed flow with the DEV-60.

But, whether that is THE problem or not, depends on what's between the filter and the pool.

How have you been cleaning the membranes? If you've acid cleaned them, that can be a problem.

[mas985]

A large pump is going to have high head loss and 46' of head (20 PSI) on the return side is not unreasonable so I would consider that within the normal range for that pump. Also, most DE filters with backwash valves will be on the high side when it comes to head loss.

[PoolDoc]

Mark, the 15% increase in 'clean filter' pressure suggests a problem with the membranes.

Also, on most filters, the pressure gauge is installed downstream of the multiport, and measures only 'back-pressure' from the filter itself + any gear down stream of that. He's starting off with ~60 of head, and going up from there.

[mas985]

Sorry, I guess I misunderstood the post.