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benzo
09-17-2009, 11:23 AM
I've seen mixed reviews and water softener systems w/ and w/out gravel beds. The folks selling resin tanks w/ gravel beds argue you need it, the ones who don't say its not necessary for softening alone. Care to comment? I'm looking at a 48k grain system for my new home.

biermech
09-17-2009, 03:14 PM
Underbedding is put in the tank for several reasons. It helps to prevent channeling, keeps resin out of the slats and prevents the baskets from expanding during backwash. I prefer to use underbedding with all my units. I"ve seen unit without it and I've seen units with it. So it will work with it or without.

Gary Slusser
09-17-2009, 09:25 PM
There is no disadvantage to a gravel underbed except the small cost. The primary advantage is a reduction in pressure loss across the softener.

There is no advantage to not having a gravel underbed.

nhmaster
09-18-2009, 11:19 AM
Three for gravel under bed.

pspitael
08-22-2012, 07:43 AM
Aside from the cost - does adding the 4-6 inches of gravel diminish the required freeboard area above the resin? How does that impact backwash efficiency?

ditttohead
08-22-2012, 09:26 AM
The gravel cost is minimal, average less than $1 per system. We buy it in bulk, 40,000 pounds a couple times a month.
17108
As to calculating water softeners capacities and freeboards etc, industry standards state that only the non domed areas are to be calculated for resin capacity and freeboards. The domed sections are not part of the calculation. The gravel should only fill the domed section in the bottom of the tank. I have attached a picture that shows this.

Many companies use a smaller tank to save a few dollars, and they do not use a gravel underbed. This is improper, but in all reality, it will work fine. it is bad practice. Other system designs, Vortech tanks, and Turbulator do not use gravel underbedding.

There is no disadvatage to gravel, other than the slight weight increase for shipping. The units that do not use gravel and claim "incredible performance advantages to systems with gravel" are mostly marketing hype. If the advantages were that amazing, then why is it only used in the most common tank sizes, and not on huge commercial equipment where the advantages would be worth while? These designs are not bad, they are primarily just marketing.

pspitael
08-22-2012, 02:40 PM
Thanks Dittohead - your picture illustration is helpful

So a quick follow-up. You state that companies tend to not use gravel and undersize their tanks. From your illustration, seems like the 50% freeboard is 50% of the RESIN volume (not the total TANK volume?). So for instance, a 1.25 cu ft system seems to commonly come in a 10x44" tank - which has a volume of about 2.0 cubic foot. Add 1.25 cu ft resin, and 0.75 cubic foot freeboard - is that sized about right?

And a related follow-up. If I were to take that same tank (10x44) and add just enough gravel to fill the bottom dome (and most of the distributor?) - that really shouldn't effect the amount of resin needed and the available freeboard, correct? Or would you upsize the tank to a 10x54 (commonly sold for 1.5 cu ft resin?).

Thanks!

Gary Slusser
08-23-2012, 05:44 AM
A 1.25' softener is an oddball size and many web sites and local dealers do not sell them. Other than big box brands most softeners are sold in whole and half cuft volumes of resin.

A 1.5 cuft has a larger constant SFR.

pspitael
08-23-2012, 07:32 AM
Thanks Gary. I was waffling between a 1.25 cu ft and 1.5 cu ft unit, so may be better off going with the 1.5 cu ft. If I do go with gravel, I'll have a bit more room to work with in the taller tank.

Per my question above, am I correct in assuming that the 50% freeboard volume is based on 50% of the resin volume (1.5 cu ft resin would require 0.75 cu ft freeboard?)

Dittohead - must be nice buying gravel in bulk - I see prices of $40 or more per 15 lbs online - that's a bit more than $1 per unit :). I'll have to try and get some locally.

ditttohead
08-23-2012, 09:16 AM
LOL, yeah, our gravel comes by the truck load, and they fill our super sacks on site. I have recalculated, and the cost per 1.5 cu. ft. unit is actually much lower than I said. We charge for repacking, shipping, handling, etc. You can get gravel locally, just be sure to put it in a bucket, and rinse it well with a bleach and water solution before putting it into your system.

You assumption on the freeboard is correct, the freeboard is based on the resin height. Our calculation are / .66 to get your resin/freeboard height. Remeber to remove the domes portion of the tank away from the equation. All this being said, it is not that crititcal, it is just the standard practice that allows for a lot of variance in water temperatures, pressures, etc, and the systems will still work almost anywhere in the world without problems.

pspitael
08-23-2012, 09:45 AM
Is there any 'magic' about the type of gravel needed? I'm assuming somewhat small and uniform would be ideal - but do I have to go to great lengths to get the perfect gravel? I'm wondering if a pet supply place might have something that would work.

ditttohead
08-23-2012, 10:39 AM
Just use 1/8 - 1/4" gravel, do not use the colored types from a pet store. Standard, irregular gravel is preffered, but gravel that is slightly "rounded" will work well too. Home Depot, Lowes, etc. should have generic gravel for underlayment. Be sure to clean and sanitize it prior to putting it into your softener. I would highly recommend buying a bag of NSF certified gravel from online, but it will be very expensive due to thehandling, shipping, etc. We get our gravel from an NSF certified supplier, they sell the exact same gravel to the road buuilding companies.

My only real concern is the contaminants that can be present in an unknown gravel source.

Gary Slusser
08-24-2012, 05:52 AM
Thanks Gary. I was waffling between a 1.25 cu ft and 1.5 cu ft unit, so may be better off going with the 1.5 cu ft. If I do go with gravel, I'll have a bit more room to work with in the taller tank.

Per my question above, am I correct in assuming that the 50% freeboard volume is based on 50% of the resin volume (1.5 cu ft resin would require 0.75 cu ft freeboard?)

Dittohead - must be nice buying gravel in bulk - I see prices of $40 or more per 15 lbs online - that's a bit more than $1 per unit :). I'll have to try and get some locally.
The best is to get the correct size based on your peak demand flow rate. And using water treatment gravel from an online or local dealer than playing around with gravel from somewhere else.

Tom Sawyer
08-24-2012, 06:08 AM
Yea, what does get some locally mean? Are you going to head to the back yard with a bucket and a shovel? Look at the expense this way. That's 40 bucks over 20 plus years. Pretty cheap really. And go with the 1.5 cu. ft. while you are at it.

Gary Slusser
08-24-2012, 07:06 AM
Hey. I've been meaning to ask you.... what's wrong with plumbers that they require a license when rocket science doesn't?

Tom Sawyer
08-24-2012, 09:48 AM
When a rocket goes bad a few people get killed or hurt. When you cross connect sewage with potable water or chemical waste with potable water, entire cities get killed or sick. Hey, next to hookers we are the oldest "profession"

Gary Slusser
08-24-2012, 01:01 PM
Wow, without a license plumbers don't know how to do that?

As you know I have never had a plumber's license so... I suppose their instructional pictures are on the back of the license?

ditttohead
08-24-2012, 02:24 PM
A question of that caliber is really hard to respond to. I suppose licensing electricians is not necessary as well? Construction codes? Building codes? Fire safety? All of these work together so we dont have buildings collapse, fire suppression systems that dont function when needed, safe water, etc. I really do not see a need to go this direction other than to troll. Lets try to help out the OP and not drag this into the gutter.

thanks,

Tom Sawyer
08-24-2012, 05:47 PM
In the beginning the idea was to license plumbers because of the apprentice system of training. In that system the abilities and responsibilities are broken down by time and experience, at least ideally it is but as we all know, anytime governmental types and groups of special interest folks get involved the whole thing begins to rot. Kind of like oru present government. Still, there are any number of trades and professions that require licensing and with all trades and professions there will be competent and skilled ones and those that slide in under the wire or maybe even pay their way to a license. I can't help that and I'll freely admit that the process is flawed and in fact I have been fighting with the state plumbing board for 10 years now to change the process. As you know, government moves slowly unless there is a direct benefit to those in charge. In the end though, I ask myself if I knew nothing about plumbing would I want someone with a license in my house or not?

So I take it the fishing was good yes ? LOL Would have been a whole lot easier to just come out and ask though. I would have told you.

mialynette2003
08-25-2012, 04:21 AM
The best is to get the correct size based on your peak demand flow rate. And using water treatment gravel from an online or local dealer than playing around with gravel from somewhere else.Isn't it a requirement that insurance agents have a licence? Now why would that be?

Gary Slusser
08-25-2012, 06:22 AM
Yes there is and the reason is as ridiculous as the reason for a plumber's license. Or private pilot's license. Or driver's license. There used to be a license required if you owned/operated a CB radio too. Still is for HAM radio. There are hunting and gun licenses too.

The reason is an ever increasing in size and scope, tax'n spend, freedom reducing anti business lying democrat controlled government using consumer/public safety as the cause for their licenses and regulations.

Tom Sawyer
08-25-2012, 06:33 AM
So I take it Obama will not be able to count on you for your vote LOL

LLigetfa
08-25-2012, 07:05 AM
Your behavior on this forum is deplorable and not fitting a moderator. You take almost every thread here into the gutter with your off-topic rants and antics.

It's too bad Terry is more interested in the ad-click revenue from traffic following your antics than serving the needs of people coming to this forum looking for help.

If anyone wants to start a petition to unseat Gary as the moderator, you have my vote.

Tom Sawyer
08-25-2012, 07:36 AM
He hasn't been a moderator for quite awhile now. I'd hate to see him go. He makes me laugh.

Airline pilots have to be licensed. I think that's probably a good thing. Not that someone couldn't have those skills without having a license but how do you keep track of their experience otherwise? Maybe we should get rid of drivers licensed too. Lord knows there are thousands of folks out there driving with licenses that haven't a clue. Anarchy is the way LOL

Rather than complaining though, how about coming up with a viable solution to the problem. One that gets the government off our backs and yet still keeps innocent folks from getting hurt, killed or robbed blind.

BTW, this has got to hold the record for the furthest thread drift in the history of forums LOL

Just a reminder though Gravel under bedding was the original topic

LLigetfa
08-25-2012, 10:14 AM
He hasn't been a moderator for quite awhile now. I'd hate to see him go.

Are you talking figuratively? Who is moderating this forum?

I'm not trying to ban him from the site. Maybe Terry could setup a Gary's Corner forum where his rants and antics would be acceptable. I just want this forum to have some modicum of decency and professionalism and not have every thread dragged into the gutter regardless of how entertaining it may be for you.

Tom Sawyer
08-25-2012, 10:23 AM
I guess Terry is moderating it. We do tend to go off on tangents though no doubt. Still, it's been a lot more civil around here lately than in the past. I guess we're just used to it by now.

ditttohead
08-25-2012, 12:43 PM
At least the petty veiled theats and disclosing of private information has stopped, and now that he cant go into threads and change them and delete items he disagrees with... regardless, the number of people that read through a few posts looking for an answer prior to asking and wont post because of ridiculous trolling and petty gutter work that is always done when someone starts putting in their 2 cents must be staggering. Look at threads that some were not commented on by... and notice how simple, clean, and to the point they are? A disagreement on technique, a difference of opinion, a different way of accomplishing the goal maybe, but the ridculous rants, trolling, and passive aggressive behavior just doesnt occur. It is the same on almost any other site, wether it be water, well, or whatever.

I agree, gravel underbedding is a good practice, while not totally necessary, and the vortech tank is a good design, though more difficult to service in the future and a little more expensive up front.

3 pages for a question on gravel??? With a side rant of anti-government thrown in for good measure. All government licensing is bad, all government is bad??? Sigh, I am very conservative, very republican, but even so, I can understand the need for "limited" government. Then again, this particular rant is coming from an unlicensed person who lives in parking lots. :)

Gary Slusser
08-25-2012, 05:59 PM
Yo guys... the thread is just two weeks short of 3 yrs old! And was resurrected with one recent post about the original subject by an other than the original poster. And then my good buddy Tommy derailed the thing in post #14...

Well that's if you don't include 20tons' truck loads of gravel a month etc. etc. but...

I see I have not said one word, until now and in response, about anyone here and yet I see 3-4 guys running me into the ground personally... while whining because they are a bit too sensitive, or feminized, I guess... or following an agenda. I go with the latter although all three seem to be true. Oneof'em is from outside of the US.

I also notice I'm the only non anonymous one here.

Anyway, Tommy I won't be voting for any RINOs either. And I'm thinkin' ya oughta get rid of the piper cub thingy, save the license renewal money for it and all them plumber licenses you've got and get yerself a few more beans, bullets'n bandaids; ya know, just in case.

Which reminds me... you might want a bit of rice, flour, sugar, etc. and a means to boil water to make potable water without being 'plugged in', like in a parking lot or some such.

Tom Sawyer
08-25-2012, 06:33 PM
I'm not really sure how my agreeing with you in post #14 derailed the thread and for the life of me what is the 20 tons truck loads of gravel a month about? Are you back on the bottle again cause that just makes no sense whatsoever. Now as for buying beans and rice, that's a good strategy for some but that means that you have to spend all your time defending your castle. It's gonna be a 24 hour a day job, 365 days a year. Better to be the looter. At least you get a few days off to rest in between raids. LOL As for licensing the piper, if I lived in a more secluded area I'd probably consider it but I'm only about 5 miles from the nearest MOA to the north and I have Pease AFB, Manchester and Logan airspace to the south. Not registering would probably cost me way way more. BTW, it's not a cub, its a 1939 Stinson HW75. One of only a half dozen left in the world at last count.

Mikey
08-26-2012, 05:10 AM
Ah, creeping right along... an HW75? A real oldie but goodie. I owned a 2nd cousin twice removed, an L-4, for a while until Hurricane Andrew trashed it. And of course Stinson ultimately became part of Piper, so we were part of the same big aircraft family. Do you fly on skis during the Maine winter?

I admit the thread creep and mild rants really don't bother me much, and actually (to me) add something to the social karma of the forum. I'm not crazy about the personal attacks, but every long-lived forum I participate in has them, so I've learned to tune them out. One forum did have a specific almost-no-holds-barred area called "The Cage", to which offensive posts were moved, and some posters restricted (a "time-out") until they agreed to play nicely. It was a pretty entertaining area to visit.

Back to gravel, I found 2 bags of store-bought gravel in my shed as I prepare to overhaul my system. One looks like Florida Chatahoochee stone: rounded, mixed shades of brown; the other is sharp-edged, uniform and white. I guess the ideal underbedding wound be perfectly round, uniform, fairly heavy, and inert -- like gold beads. I see garnet is available -- is that special in some way? I found a 10" diameter mixing bowl in a garage sale for $0.25 a while back which is perfect for measuring out the right amount of gravel to fill the bottom dome of my tanks.

Finally, most folks say to use "1/8in - 1/4in" gravel. I wondered exactly what that meant. (Yes, I do have too much time on my hands.) My first guess was the individual pieces of gravel were between 1/8" and 1/4" in some dimension or other, but that didn't seem very scientific, and measuring a bucket load of gravel would be tedious (although, believe it or not, they use lasers and digital imaging to do just that these days). But Googling eventually led me to "Sieve Analysis", which is probably what's really going on. (This is a Civil Engineering discipline. As an EE, I find it suspect from the get-go.) If so, the 1/8" - 1/4" size means that if you've got a bucket of gravel, and sift it through a 1/4" screen, and then sift the result through a 1/8" screen, you will be left with "1/4in - 1/8in" gravel on the top of the 1/8" screen, and can throw everything else away.

Tom Sawyer
08-26-2012, 07:20 AM
I actually bought the HW75 from a friend that was restoring an L4 to original military dress so he needed the money for the project. It originally had a Continental 65 which was underpowered to say the least. It's got a Lycoming 0235 in it now. Never had ski's on it that I know of.

Gary Slusser
08-26-2012, 08:42 AM
Back to gravel, I found 2 bags of store-bought gravel in my shed as I prepare to overhaul my system. One looks like Florida Chatahoochee stone: rounded, mixed shades of brown; the other is sharp-edged, uniform and white. I guess the ideal underbedding wound be perfectly round, uniform, fairly heavy, and inert -- like gold beads. I see garnet is available -- is that special in some way? I found a 10" diameter mixing bowl in a garage sale for $0.25 a while back which is perfect for measuring out the right amount of gravel to fill the bottom dome of my tanks.

Finally, most folks say to use "1/8in - 1/4in" gravel. I wondered exactly what that meant. (Yes, I do have too much time on my hands.) My first guess was the individual pieces of gravel were between 1/8" and 1/4" in some dimension or other, but that didn't seem very scientific, and measuring a bucket load of gravel would be tedious (although, believe it or not, they use lasers and digital imaging to do just that these days). But Googling eventually led me to "Sieve Analysis", which is probably what's really going on. (This is a Civil Engineering discipline. As an EE, I find it suspect from the get-go.) If so, the 1/8" - 1/4" size means that if you've got a bucket of gravel, and sift it through a 1/4" screen, and then sift the result through a 1/8" screen, you will be left with "1/4in - 1/8in" gravel on the top of the 1/8" screen, and can throw everything else away.
You don't want uniform or garnet (IMO), 1/8" x 1/4" has been used for many decades because it is the best size and shape.

You pour the gravel in the tank after plugging/taping the top of the distributor tube to keep gravel and resin out of the DT and putting the distributor tube in the tank and holding the it down in the tank so the pointy end of the bottom basket on the end of the distributor tube is in the dimple in the center of the bottom of the tank.

When taking a plug out or tape off the DT You do not allow any gravel to get under the bottom basket or it will eventually break the bottom basket and allow gravel and then resin out into your plumbing and all fixtures. That can be a nightmare to clean up and expensive.

You only add enough gravel to cover the top of the bottom basket by an inch and quit.

ditttohead
08-26-2012, 09:43 AM
Your seive explanation is correct. Garnet is always better than traditional gravel, but from a cost point, it is considerably more expensive. (it is still extremely inexpensive though). The typical garnet for water softening is a 8-12 mesh. Many of our customers spec garnet over gravel, but it is purely for marketing reasons rather than actual function. The garnet is also much cleaner than even the expensive triple rinsed gravels.

Sounds like you are good to go!

Mikey
08-26-2012, 11:01 AM
Sounds like you are good to go!

I hope so. I've been putting this off for years as I accumulated supplies and information. The first link in the chain is draining and pressure-washing the 120 gallon contact tank, but the %$#$ pressure washer won't start. It's one d*mn thing after another.

Gary Slusser
08-26-2012, 01:03 PM
Garnet is always better than traditional gravel,

but from a cost point, it is considerably more expensive. (it is still extremely inexpensive though).


Many of our customers spec garnet over gravel, but it is purely for marketing reasons rather than actual function.
Your customers are mostly wholesale distributors that then sell to plumbing supply houses, that then sell to plumbers and well drillers etc. right?