Settings for Fleck 5812 SXT w/ 2.5 cu-ft Resin Tank

[Dmlaero]

Do the settings below look correct? Seems like the capacity should be more like 60,000 grains to be closer to the "ideal" salt dose of 8 lbs per cu-ft (@24,000 grains/cu-ft).

What actually controls salt dose? I assume the BLFC and Injector have a role, but do any of the settings affect it, like brine draw time?

BLFC: 0.25 gpm
DLFC: 4.0 gpm
Injector: 3
------------------------------
DF: GAL
VT: 5812
RF: dF2B
CT: Fd
C: 70.0
H: 20
RS: cr
DO: 21
RT: 2:00
B1: 7
BD: 60
B2: 3
RR: 7
BF: 27
FM: t1.2
RE: OFF
VR: OFF

 

[Bannerman]

You are correct regarding the capacity and salt dose expectations.

24K/cuft X 2.5 = 60K usable capacity (C)
8 lbs/cuft X 2.5 = 20 lbs needed per regeneration

The brine fill (BF) time in minutes X BLFC (in gpm) = the total quantity of water to refill the brine tank after each regen cycle. Each 1 gallon will dissolve 3 lbs salt.

The injector will control the Brine Draw and slow rinse rates. In a typical 60 minute BD cycle, the brine will be all drawn within approx 15 minutes, leaving 45 minutes remaining for the brine to continue flowing through the resin, and be rinsed to drain.

Your current 27 minute BF setting will dissolve 20 lbs salt, but the Capacity setting should not be 70 but needs to be reduced to 60.

 

[Sponsor]

 

[Reach4]

I concur.

With your #3 Yellow injector, your brine will be drawn in about 11 minutes.

 

[Dmlaero]

Thank you, Bannerman and Reach4, for your explanation...easy to understand. So, ultimately it is the BF time that determines salt dose as it controls the number of gallons of water put into the brine tank to dissolve salt at 3 lbs/gal for the next regen.

My old brine tank had a salt grid on the bottom (new one doesn't). What are your thoughts on these? Does this allow the water line to be lower by holding the salt up off the bottom? I currently have 3 bags of salt in the tank but it isn't covering the water yet.

 

[ditttohead]

Brine grids... many companies claim thy prevent bridging etc, they don't. In reality they simply allow for the installation of a smaller brine tank. This is very useful when space is at a premium. The disadvantage is that you will have less salt storage so refilling the brine tank will need to be done more often. Larger grids tend to create more problems as they are trying to support thousands of pounds of salt and they tend to break over time. Smaller residential systems... no problem as these grids are only supporting a few hundred pounds.

 

[Reach4]

I can't picture how a salt grid would prevent bridging. I do picture the salt grid giving insolubles a place to settle and allowing less salt to be discarded when cleaning a small brine tank after maybe 1500 pounds of salt. So if it saves 25 pounds after 1500 of salt used, I guess that is small in the scheme of things. The 25 and 1500 are my SWAGs with nothing to back them up.

The salt grid is not going to let the water level be lower. The the air check valve level determines how much brine gets sucked out. Brine fill starts from this level. The higher that air check is, the higher the level after fill.

 

[ditttohead]

Some salt is really nasty/dirty. Salt tends to be regionally sourced due to shipping costs. I used to be a salt salesman, many many millions of pounds per year. Cheap solar sal that was fairly clean. It came from Guerro Negro in Baja by ship. An 18x30 could go through about 10,000 pounds before cleaning was really needed. Not to bod. Some of the really dirty salt, maybe a couple thousand pounds before we had a couple inches of dirt/debris. The grids simply displaced the salt allowing for more water to be in the same brine tank. We used to build custom grids as big as 60" diameter. These were very difficult to build at a reasonable cost so they were usually built pretty cheaply and they would not last more than 10 years if we were lucky. Smaller grids up to 36" were no problem and would last decades without a problem. But... the dirt underneath was nasty and the grids had to be removed to properly clean the brine tanks. For the most part grids should be avoided. Many of the Chinese brine tanks use them to keep the brine well in place since they tend to sell only nestable brine tanks which saves on container shipping costs.

Class dismissed. Now go have a great 4th of July! I will be working...