Sounds kind of high to me too Mike. I am now in the wholesale distribution side of the business, supplying the service and building companies. This sounds like someone that is going to buy the filter at Leslie's, and then charge you a markup and installation. This was from the builder? I do have customers that won't install products you got on the INTERNET. Some will, but they charge more. Most won't be responsible if something goes wrong. I have seen websites selling products we sell, for nearly our cost! I guess if they never touch it,they don't need much profit margin. The manifold and one grid is not a hard repair. I would be careful handling the old the grids. If you take your time, you can probably do it. Be sure to tighten the belly band properly when your done. Good luck.

Thanks. Scott! I replumbed the filter. My slide valve is sticking and hard to move.I finally got it all the way up and restarted but water shot out the bottom waste like it was backwashing. I did hear a pop sound so perhaps something blew inside the slide valve? It's the Pentair Model 261165. Do you advise taking it apart and trying to replace O rings etc and perhaps lubing the rod, replacing it or getting rid of it altogether? The slide valve is only for backwashing isn't it?I usually take the filters out to clean them so don't see a real need to have backwash capability. Also, I have a Pentair 320 inline chlorinator. The feeder hose snapped off. I was advised to just remove it since it raises CYA. Have a pool leak so putting water in alot so until I can get that fixed, should I use it? Do I need a check valve on the pressure side before or after this 320? Thanks, Ed

One thing I'd recommend doing is taking a few baseline readings on your system. You'll need the water to be pretty clean and clear before you start, but I'd start by opening up the filter and completely cleaning the grids. Seal it back up, set your valves to the "normal" position (make sure to write down how you set the valves), and start up. Take measurements of the system pressure at each of your 4 speeds. This will be your "clean" baseline reading. Now charge the filter with the DE to the recommended amount. (Personally I'd use Zeofiber, it does an even better job and is not as nasty as DE and easier to dispose of) Give the system some time to normalize and evenly coat the filter grids, and take the same readings at each speed. (note, the valves MUST be in the same position for all these pressure readings, and no auxiliary equipment turned on) The reason to do this is so that now you have a recorded value that the system SHOULD be when the filter is clean. If after you backwash and recharge, the pressures are different than this reading, either your backwash was incomplete, the filter is too gummed up to backwash (every now and then you will need to crack it open to wash, backwashing is not perfect), or something else is wrong in the system. Without knowing the baseline figures, it is hard to tell. Now - to determine when the filter is clogged, you'll need to use the max speed like Kelly said, since all the equipment recommendations are based on single speed pumps. (I heard 10psi, but your filter manual should say) Once you reach this amount of pressure above your baseline figure (at 3450, mind you) slow the pump down to each of your three lower speeds and take pressure readings at each case. These are now your "clogged" numbers, and you can use these to determine how dirty your filter is at any operating speed. However at the lower speeds this may only be 1 or 2 psi over "clean" pressure so it might be hard to tell - but at lower speeds the filter can take a bit more clogging so it's not as big a deal as if you were running at full speed. It'll just start absorbing a bit more electrical power until you get the filter cleaned out again, but since you're at low speed already, it's not a lot of power. Hope I didn't confuse you, and hope it helps! Variable speed is awesome, but it can be tricky. Best of luck!

First, are these two filters of equivalent size (not actual size)? Generally, a 60 sq-ft DE filter has about the same capacity as a 400 sq-ft cartridge. I know that sometimes the pressure loss does not depend on the filter size so maybe it doesn't matter. If they are comparable in size, then the difference would only be about 10 watts to get to 30 GPM (925 RPM vs 990 RPM). These of course are estimates only and your results may vary. BTW, I have a 420 sq-ft cartrdige filter on a 20k gallon pool and while they are a bit of a pain to clean, I only clean mine every 6 months (no closing) so it isn't so bad. It takes less than an hour to clean the four cartridges. Also, our city requires separation tanks on sand and DE filters which is why I ended going with a cartridge filter. I personally don't have a lot of experience with DE filters but many on this forum and other forums have. One reoccuring theme is that the grids on DE filter occasionally get clogged and require cleaning. From what I understand, this can be a messy job and not too unlike cleaning a cartridge filter. Also, after every backwashing, they require more DE. My point is that DE filters may or may not require less maintenance than a cartridge. No filter is perfect and each has pro and cons. You basically have to pick your poison. Also, what ever type of filter you choose, I would suggest that it is over sized so you don't have to clean it so often and so it cleans better.