Pentair Quad DE filter size recommendation

davidhum66

Bronze Supporter
Jul 8, 2018
24
Austin, TX
I had 2 very old FNS filters on my pool (48 sq ft) and replaced one in '16 with the Pentair quad (60 sq ft). The reason I have 2 DE's on my system is based on the recommendation of the pool company in '00 when we built our pool. The 60 quad services our pool/spa. The other one is for a catch basin that recycles water back in the pool from a negative edge and when kids are splashing in pool. We found that the winds constantly pushed water over the edge when pool was off and I was losing water out of the basin as a result. So, we have a 2 stage pump that operates on low speed at all times (unless we're swimming where have to turn on high speed mode). We also are surrounded by trees so helps with the filtering.

My question is whether or not I can put a larger size filter on the basin DE filter. Pentair sells a 60, 80, and 100 sq ft filters. My pool is 22k and the basin 2 stage pump primarily runs at .33hp (1750 RPM). The basin DE takes the brunt of the pool filtering and is much more dirty each year when I break down the filters to clean. Are there any concerns with going with the larger size 100 quad given we run this pump at low speed majority of time? I am looking to install this myself as this is considerably cheaper than the estimate I got from the pool company. I know the water flow is reversed so have to purchase a new multi-port as well. I just read the excellent post about these filters. JoyfulNoise's QuadDE Tutorial. Thank you!

The quad 100 is more expensive, but also read that it's ok to oversize filtering equipment, especially if this does the majority of the pool filtering and i'm wanting to extend time between full breakdowns. Any other thoughts before purchasing this Pentair quad? I have been pleased with the 60 as its easier to clean. Attached is a picture of the 2. I was surprised to see that the quad 60 is much smaller than the FNS 48. Thanks.
 

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jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,238
Tucson, AZ
There is no issue with going over-sized on the filter. Although certainly seems a little overkill to need both. Suppose that is just the way the system was setup.
 

kadavis

TFP Guide
In The Industry
Apr 5, 2015
1,645
tucson, arizona
Just curious how you recharge the catch basin filter. With the quad D.E. you probably could go as big as you want or your budget will allow. I have found that the quad filters don't backwash very well so I usually plan to clean them like a cartridge filter, the trick is on a catch basin there's no skimmer to put the DE slurry in.
 

davidhum66

Bronze Supporter
Jul 8, 2018
24
Austin, TX
I actually have a skimmer on the catch basin. I have it closed off most of the time given with our prevailing southeastern winds, the tree pollen/leaves gets moved fairly quickly to the large skimmer (aka my catch basin) :D and I just use the leaf rake to more quickly clean the pool by cleaning out the basin. But recharge is through that basin skimmer. Agree with your backwash comment. My quad doesn't seem to remove as much DE as before.

Thanks for the responses. I am glad the size doesn't matter in regards to the low flow pump. I'm undecided on the size. One consideration: why is there a $300 increase between the 60 and both the 80 and 100? I will try and go as large as possible, but there was another post commenting on how tall the 100 is. Clearance isn't a problem, but am interested to see if the 100 is relatively the same to clean as the 60 (or with DE caked on, its a whole lot heavier?).

On another note, this forum and owners of the quads seem split on the use of a MPV. I have liked having mine on the quad 60 I installed, but thought I needed it as I had a MPV on previous DE unit and used it 2-3x/yr. I haven't noticed my pressure increasing since I've purchased the 60. Maybe because its larger than the FNS 48? Don't know, but only backwashed once since I installed the quad over 18 months ago. But whether there is greater stress on the cartridges, the time I have to do a full clean, and some other points brought up, I will probably NOT spend the extra money on this unless I stick with the 60. But don't think I would miss it...and if its better for the expensive cartridges to not BW...and I do a full clean every year anyway, then seems unnecessary. With 2 DE's on my system, I think this too was overkill. It was certainly more expensive and at the time, I wish I had researched it a bit more. Pool co just commented that it would dramatically help with the trees and my setup. Since I really only have to clean the DE's once per yr, maybe they were right. Or maybe I just agreed to a setup with a 2nd filter unnecessarily. But can't complain about the clarity of the pool. Oak pollen here in Austin can be a nightmare for my system to handle.