10" Big blue vs 20" Big blue

[Leweezo]

Hi all, I am having issues with my well pumping REALLY fine sand. I am thinking of putting in a 100 mesh sediment trap followed by a Big Blue sediment filter. I am wondering if I am better off with a 10 or 20 inch version. My line is 3/4 and my pressure is really strong pre-filter (I have a 140 mesh spinout) I am wondering about the difference is pressure loss between the 2

Thanks for any answer
Mike

 

[Reach4]

It will be half as much for the 20 inch as for the 10.

Half of what? Depends on the cartridge. Note that the numbers they publish for pressure loss or GPM would be for when the cartridge is new.

As I understand it, the same top can fit the 4.5x10 and 4.5x20 housings. So if you have enough room, you could change later. It might cost less to buy a whole housing than to buy just a new sump (the blue part), but I don't know.

Note that the 4.5x2o housing is heavy when full of water. So you would like to be able to stand close rather than work at arm's length.

It is best to have a bypass system around the filter assembly. But if not, at least do what I do -- keep an extra O-ring handy for when you change cartridges. Usually you can reuse the O-ring, but not always. I use a light coat of Molykote 111 on my O-rings when changing cartridges.

 

[Sponsor]

 

[Leweezo]

Hi Reach4, Thank you for your reply. I definitely will have enough room for either model Since it iwill be in the unfinished side of my basement. Thanks to your post I loked up the 5 micron BB sediment filters and the 10 and 20 are rated for 5 gallon per minute. I am assuming that the bigger filter would lose pressure slower since it has more media. Is my assumption correct? If this is so, I will just buy the bigger one since I have the room and the less the loss the better.
Also thanks for the extra O ring idea, If I get the setup working the way I need it to, I might buy a second housing and always have a filter and Oring ready to go in. (since it seems to usually clog when my wife showers).. Never heard of Mollykote but I just added it my list.

Again thanks for your expertise
Mike

 

[Reach4]

I use the DGD-5005-20 Pentek Whole House filter cartridge as my first cartridge. Since you don't know what you might have, you could start with something like that. It is dual density 50 micron outer part and 5 micron inner part. Initial drop <1 psi @ 20 gpm, but that would increase as it picks up stuff. It is polypropylene. Do not use a cellulose cartridge on unchlorinated water. http://waterpurification.pentair.co...oad/en/310061-pentek-dgdseries-rev-d-my15.pdf

Doing reading, pleated filters may be better, at least for some water, than the spun filters. The subject is still open in my mind. My BBs have little left for them to do after my iron+sulfur backwashing filter removes most stuff first. I ordered them before deciding to get the backwashing filter.

You could use silicone plumbers grease, maybe $4 or $5 for a half ounce. You don't need much. The 5.3 oz tube of Molykote costs more, but it is a much bigger supply. It does last a long time, and does not deteriorate by sitting decades in the opened then capped tube, as far as I know. http://www.waterfilters.net/ge-o-ring-silicone-grease.html describes a 0.2 ounce packet of Molykote 111. I use nitrile gloves to grease and place the O-ring. Pentek 151122 is the O-Ring for 10" & 20" Big Blue housings.

 

[BillTheEngineer]

When you plumb it up, like others have said make a bypass loops for when you have to change the filter.

Like this but without the solenoid valve.

When you order the filter, order extra o-rings (cheaper to get them from a place that just does o-rings that the filter supplier most likely) also get a rebuild kit or two for the red vent valve on the unit. They have a tenancy to leak there once used. If you don't have a hose bib before the filter you may want to add one in too.

There are many filters that fit this housing, its a standard size. you may consider putting two in series if you have to treat more than one issue. end up having to use a fine and coarse filter to get a decent life out of the filters.