No air in lines, ah, yes air infiltration was likely seals or injectors needing replacing due to chlorine degradation. So that fixed that.
Currently, intermittent light brown water.
Need to replace calcite/corosex.
Manually regenerating resin tank as could be fouled resin.
 Tue, Apr 4, 2017:
"Now we know I'd been running my MTM tank without the riser tube being secured into the valve. At some point I'd decided to replace my tanks with 10x44 vortech tanks as I like the technology and compared to the 10x47 tanks I'd been using I'd have more headroom in the crawlspace. I wish I had someone to blame other than myself, but I've always tried to do it mostly on my own and I ended up somehow with a Fleck 7000 without the correct part to seat the riser tube."

As of 6/20/19
Cleaned air check in brine tank of softener.
Cleaned toilet tanks in house.
This along with all new injectors and seals and spacers should resolve any air in plumbing and iron in toilet tanks.
Check for air and iron in toilet tanks by 7/20/19.
If air remains check other two brine air checks and post question as to alternate air entry points.
If iron remains consider replacing water heater and/or softener valve.

Replaced seals and spacers on all valves (calcite, kat1, kat2, carbon, and resin).
Replaced injectors on kat1 and kat2.
Should probably replace seals, spacer, and injectors on these first three tanks every six months.
Need to add calcite (ordered) and centaur carbon (should check when last replaced).
answer: 7000 Centaur Carbon 10x44 Vortech (media replaced June 2018)
Both KatL tanks are now drawing.
Trickle down drain line from calcite tank corrected.

Recent trouble of iron in toilet tanks.
After much work I believe the problem may have been the water heater!
Flushed much rusty sediment from water heater.
Also flushed my two retention tanks.
Topped off chlorine injection tank.
So far no morning pulse of iron or air.
Other trouble includes pot perm not drawing on either kat tank.
Replaced seals and piston and cleaned kat1, no luck.
Replaced seals and cleaned kat2, no luck.
Will order new injectors.
Need to confirm programming times after this work.

As of 4/20/19
Regeneration times are corrected with no overlap.
Softener has B2 extended 5 to 6 and RR from 10 to 12.
Cleaned toilet reservoirs and installed white test tiles.
Salt and PotPerm filled.

First, it appears the time of day setting was incorrect for K1 tank such that it was overlapping with K2. Probably for the last three weeks.
Also realizing that toilet use during softener regeneration is allowing that bit of insoluble iron trough to interact with chlorine tab in toilet reservoir.
Also also, it could just be the softener needs a bit more B2 or RR so increased B2 from 5 to 6 and RR from 10 to 12.
---Time of day settings now correct and softener timing tweaked and keeping a log for use of master bath toilet.

More testing the next day late afternoon (previous samples were also late afternoon).

Soluble Iron zero

Total Iron also looks like zero

BYPASS softener

Soluble Iron zero

Total Iron about .1ppm.

BYPASS softener, centaur carbon, and second Katalox Light tank

Soluble Iron 7-9ppm

Total Iron not tested

BYPASS softener, centaur carbon, and both Katalox Light tanks

Soluble Iron 9-10ppm

Total Iron not tested

Notes:

Total system is under ideal conditions resulting in no measurable iron
Softener isn't removing much iron

Second Katalox Light tank with Centaur Carbon tank are removing a great deal of iron.

Even with chlorine injection/retention time, calcite tank, and one Katalox Light tank 7-9ppm of iron remain in water.

I would have expected half that number or even less. Is the first Katalox Light tank doing its job?

The second Katalox Light tank and Centaur Carbon tank then remove almost all of that amount with softener doing a small amount of polishing.

As ditto suggested I should: "Backwash the KL tank and see how much iron is coming out during the backwash cycle. Once the water runs clear you should add several minutes after that in the backwash cycle. Be sure to have an adequate rapid rinse cycle."

I should also test the backwash of the softener. If the softener backwash contains iron then the toilet reservoir tank problem could be due to insufficient backwash time and/or use during regeneration?

Below you first see the total iron test of water out of the softener.

Second is the total iron test of water bypassing the softener.

Third is soluble iron test of water bypassing KL2 and Carbon tanks (this result was virtually indistinguishable from the test after bypassing both KL tanks).\

Iron CHEMets Kit results, mid afternoon
Soluble Iron zero
Total Iron .1ppm, maybe, see image below.
The first is using the soluble/ferrous iron procedure.

Regeneration times

Calcite 11:00 PM
20min
K1 11:30 PM
90min
K2 1:10 AM
90min
Carbon 2:50 AM
20min
Resin 3:20 AM
116min

11 to 11:20
11:30 to 1:00
1:10 to 2:40
2:50 to 3:10
3:20 to 5:20

All tank programming (use and master) and diagnostics

Kat one
DO
FR00
PF 10.9
HR 61
VU 891
RC 120
TV 115.7
SV 3.2
UP
DO 3
RT 11:30PM
H 20
SF 10
MP
DF Gal
VT 5810
RF df 2b
CT Fd
C 24.0x1000
H 20
RS SF
SF 10
DO 3
RT 11:30PM
B1 10
BD 60
B2 5
RR 10
BF 5
FM t1.2
RE OFF
VR OFF

Calcite
Diagnostic
FR 00
PF 2.9
HR 13
VU 116
RC 120
SV 2.4
User
DO 3
RT 11:00 PM
H 20
Master
DF Gal
VT dF2b
CT Fd
C 24x1000
H 20
RS SF
SF 10
DO 3
RT 11:00 PM
B1 10
B2 0
RR 10
BF OFF
FM t1.2

Kat 2 (third)
DO
FR 0.0
PF 9.4
HR 60
VU 553
RC 123
SV 2.4
User
DO 3
RT 1:10
H 20
Master
DF Gal
VT dF2b
CT Fd
C 24x1000
H 20
RS SF
SF 10
DO 3
RT 1:10
B1 10
BD 60
B2 5
RR 10
BF 5
FM t1.2

Carbon (fourth)
DO
HR 11
SV 2.4
User
DO 2
RT 2:50
Master
DF Gal
VT Fltr
CT tc
DO 2
RT 2:50
BW 10
RR 10

Resin (fifth)
DO
FR 0.0
PF 3.2
HR 40
VU 179
RC 317
SV 2.4
User
DO 3
RT 3:20
H 20
Master
DF Gal
VT dF2b
CT Fd
C 31x1000
H 20
RS SF
SF 20
DO 3
RT 3:20
B1 10
BD 60
B2 5
RR 10
BF 21
FM t1.2

Replaced RESIN and CALCITE.
Iron problems continued as detected via toilet reservoirs.
Noted a surge of iron on first opening J bath spigot.
Could this be a regeneration issue? Otherwise water appears good.
Replaced fine mesh resin. Valve appeared very clean.
Cleaned and replaced calcite. Valve appeared iron coated, but otherwise normal.
PotPerm and salt being utilized normally.
Will check programming information and valve cycling.

notes

Prompted resin regeneration for last night, Saturday night, with tank having 750g or so remaining. Today water looks good and no detectable iron in J's reservoir. Could be resin is now clean. Could be that when all valves are set to regenerate that they step on each others scheduling or that just the resin valve gets stepped on. Should review all regeneration clock settings.

Water mixed.
As of 2/2/19 water looks good and J's toilet reservoir has no signs of iron accumulation around Clorox tablet. Will next scheduled resin regeneration result in continued clean water or will it leave water with iron residue? This regeneration should occur around 2/4/19 or so, say Monday or Tuesday. So, I'll be checking every day, but by next weekend I should have a decision/results 2/9/19.
If a problem resurfaces should replace resin, clean valve, and review status of check valves. If it looks like trouble early I'll order resin right away. Should it be fine or regular mesh?

Trouble Again

Water currently in the A range
After the media updates and manual regens our water was looking great for a few days, but after about five days, around 1/22/19 I noticed a bit of iron bleed through. All the toilet tanks being regularly used showed mild evidence of iron in the reservoir tank. So, I conducted a couple of manual softener regenerations with resin cleaning and water looks as stated above, A range.
I purchased two clear backup checkvalves. For the installed check valves the before filtration and after filtration pictures are somewhat alarming. But hey, shows the filters are doing their job.
The second clear check valve is plumbed before the water softener (due to the fact I have a T junction to provide unsoftened water to the kitchen and installed check valve was concerned the split-off might somehow unseat the softener resin). Three points, could the first valve be fouled? Now that I have backups I could replace it and see. Also, it's a bit surprising that my chlorine injection and retention leaves the water still looking like mud. I do have terrible water. Finally, is this pre-softener near pristine check valve suggesting that any iron bleed through is occurring in the softener? The iron my not be visible as the conditions are not the same as in a toilet retention tank (no chlorine tablet, less no flow conditiion). Even if it were to be interpreted this way it would still suggest that iron is making it to the water softener such that the softener is iron polishing the water. Purchased 50 lbs of calcite. Am currently deciding whether to replace resin before doing anything. Also, ordered two 25 lb salt block and am considering these as a backup/adjunct to pellet salt.
a) have backup clear pvc check valves
b) have calcite
c) ordered salt blocks
b) evaluating resin
Pre filtration and post...

Corrected

Water A+
The manual regenerations and media fills seemed to have corrected the problem.
Calcite needs filling.
Also, I'd still like to replace one check valve and I think I need a new bladder on my well pressure tank.
If a problem resurfaces I'll need to check for backwash leaks, as always, and inspect the first PVC check valve. Otherwise, confirm all media is topped off and manually regen as necessary.

Trouble

Water C-

The last few days water in toilet tank (the reservoir part) has been dark brown and one toilet has been generating a gritty brown ring. I've never seen such a ring before.

Note that is is after six months of perfect water.

Today:

Do not hear any dripping down backwash lines

Do not note any flow indicators activating when they shouldn't be (which would suggest leaks)

Noted that one clear check valve has such brown water cannot tell if it is fouled.

Would be interesting to see if clarity of water clears with chlorine replenishment.

Cleaned resin twice with one cup Iron Out and manual regeneration.

Added 80 lbs salt

Added one gallon Clorox and water to stenner pump reservoir.

Added 76 oz pot perm to each reservoir.

Noted that calcite/corosex is mostly depleted.