Brine Draw Calculation

[Lcodd6]

I'm looking at improving my Softener to make it more efficient based on the actual conditions. I'm currently using a Autotrol 960 ProSoft Control. I know it's obsolete but it's still working great with no issues. The question I have is about calculating the Brine Draw. The manual includes a table but my softener was set up with a different injector then what's listed in the table. My unit is current using an H-Injector. Is there a formula or calculation that I can use to figure out this value?

My understanding is I can improve my efficiency by changing the Refill Control valve and Brine Draw to match my water pressure. The manual I have doesn't provide a lot of details on how to calculate these values. Any help would be greatly appreciated.

 

[Lcodd6]

I guess there isn't a clear easy answer. It seems like they really want to follow the basic setting and not fine tune your system.

 

[Sponsor]

 

[Reach4]

During the brine draw cycle, how long does it take to draw out all of the brine? Typical is maybe 15 minutes plus or minus 5. The Autotrol 960 makes it really easy to see how long it takes to draw out the brine. Watch the ball in the clear housing. When the ball falls to the bottom, the brine has been sucked out.

Then whatever time that is, you usually make the brine draw 60 minutes, or 3.5 the time to draw the brine -- whichever is bigger. People usually say 4x, but I think that builds in a little extra margin. The symptom of BD being too short is a little residual salt in the first water you draw after regen.

If you find you draw your brine in under 10 minutes, get a smaller injector.

 

[Lcodd6]

During the brine draw cycle, how long does it take to draw out all of the brine? Typical is maybe 15 minutes plus or minus 5. The Autotrol 960 makes it really easy to see how long it takes to draw out the brine. Watch the ball in the clear housing. When the ball falls to the bottom, the brine has been sucked out.

Then whatever time that is, you usually make the brine draw 60 minutes, or 3.5 the time to draw the brine -- whichever is bigger. People usually say 4x, but I think that builds in a little extra margin. The symptom of BD being too short is a little residual salt in the first water you draw after regen.

If you find you draw your brine in under 10 minutes, get a smaller injector.

One weird thing I noticed yesterday in my owners manual, it says the backwash time should be 14 minutes but it's set to 4 minutes. I'm not sure why it would be set that low but I'm going to change it back to 14 minutes.

My System information:
- Autotrol 268/960HE
- Capacity: 26,200 grains @ 5.2 lbs of salt
- 10” Tank (1.56 cuft resin)
- Refill: .33 gpm
- Drain Valve: No. 10 (2.5 gpm)

 

[Reach4]

14 minute backwash for a softener seems high.
10 minutes is common, and 5 is usually enough to wash out stuff that might have gotten picked up.

I just looked at the manual at the default column. You are not going to use the other defaults, so I would not take those numbers as suggestions.

 

[ditttohead]

14 minute backwash is a bit high. While the resin manufacturers recommendations should be followed, we can also use extensive field experience to come to other conclusions. In general, under residential application a 5 minute backwash is adequate. Some of the very early automatic softeners did not have anything other than a simple brine/slow rinse cycle... these systems did fine for decades. As to the brine draw calculations, a good starting point is to set the brine/slow rinse cycle to 3-4 times the length of time it takes to remove all the brine from the brine tank.

 

[Lcodd6]

14 minute backwash is a bit high. While the resin manufacturers recommendations should be followed, we can also use extensive field experience to come to other conclusions. In general, under residential application a 5 minute backwash is adequate. Some of the very early automatic softeners did not have anything other than a simple brine/slow rinse cycle... these systems did fine for decades. As to the brine draw calculations, a good starting point is to set the brine/slow rinse cycle to 3-4 times the length of time it takes to remove all the brine from the brine tank.

thank you, this helps

 

[Lcodd6]

I found out yesterday that the Autotrol 960 Series manual has a error regarding the injector callouts. The correct injector for my application is the Light Blue "J". This making calculating the Brine Draw value using the reference table #4 in the manual, impossible. This value isn’t time, but a value for the controller to calculate the brine draw time.

I set my Brine Draw Value to 37 and ran a Regen cycle. I timed the brine draw at 11 minutes but there was still a lot of brine left in the tank. My question is, do I keep increasing this number until all the brine is removed from the tank?

Also, I will be taking the brine float out this weekend to ensure it’s clean and there aren’t any issues.

 

[ditttohead]

The "brine and slow rinse" cycle is just that. It should draw all of the brine out of the brine tank (minus a couple inches that the tube wont reach) in about 10-20 minutes... once the tank runs out of water, the system continues to run water through the injector but since the brine tank is empty no more salt will be drawn in, this is considered the slow rinse cycle. The slow rinse cycle should be long enough to clear alll of the salt out of the system. The rapid rinse is not intended to be used for that purpose.