Problem with cloudy in-ground pool. Brown residue on liner.

[crosspoint]

The brown residue started out as what looked like "sand" mostly in the seams of the liner. On one day the entire bottom of the pool had a layer of this stuff and when I put the Aquabat cleaner in you could clearly see the tracks of where it was cleaning.
After I put the HTH clarifier in and ran the pump ovrnight the next morning the pool seemed clear but wth the residue on the liner. After putting in the Aquabot and running for awhile the water clouded up.

I am pretty sure we do not have much iron in our well water. We test it often and use it as our
potable water source. There are no iron stains where we use the sprinkler, etc.

Could there be another issue?

[PoolDoc]

After I put the HTH clarifier in and ran the pump ovrnight the next morning the pool seemed clear but wth the residue on the liner. After putting in the Aquabot and running for awhile the water clouded up.

Sounds like the clarifier settled it out, but then the vacuum re-suspended it in the water. I'm guessing it's really NOT sand-like (heavy, sinks rapidly, can be felt as grainy) but more dust-like (not heavy, floats away if you create a current by waving your hand or pool brush, can NOT be felt as individual grains)

Questions:

1. Have you cleaned your filter this season (as in, took it apart and washed clean)? <= Forget this; I misread the chart, and thought you had a DE filter.
2. Do you have a manual vacuum, like this:

Poolmaster 27514 Classic Full View Triangular Vinyl Liner Vacuum @ Amazon OR
Poolmaster 27200 Premier Heavy-Duty Flexible Metal Handle Vacuum @ Amazon

Hydro Tools 8365 8- to 16-Foot Adjustable Fluted Premium Fluted Telescopic Pool Pole, White @ Amazon
Poolmaster 33430 Premium Vacuum Hose with Swivel Cuff, 30-Feet by 1-1/2-Inch @ Amazon

3. Do you have a multiport valve on your filter?
4. Is it light tan (ie, the color of dirty DE powder)? <= Forget this one, too.
5. Have you tested your filter with DE powder, to see if it 'leaks' dirt back into the pool? <= New question

[crosspoint]

The residue is more dust like and floats away if you make a curent.
I stopped using the Aquabot and went to manual vacuuming.
I backwash amd rinse after each vacuuming session.
I also shocked the pool with liquid chlorine an am running the filter continuously.
The pool water is clear with the following readings.
PH - 7.5
FC - 5 - OTO
Alkalinity - 80
Hardness - 300
CYA - 30.
Still vacuuming up some remaining residue.

[Watermom]

It would really help if you had the good Taylor K-2006 kit because your readings would be much more reliable and your chlorine test could read higher than 5ppm. Plus, it would help us to know your CC reading.

An OTO kit can only read chlorine levels to 5ppm so your chlorine may be higher than 5. 5 is not shock level for any pool. You can force your kit to read higher by using a dilution method described here: Testing Without a Good Kit

What kind of liquid shock are you using. (What percentage sodium hypochlorite is it?)

[crosspoint]

Purchased the Taylor Kit online from Amazon as you suggested. Should arrive on Monday.
I am using 6% Bleach and added 2 gallons yesterday.
I just added a CYA tab to my pump filter. Was that a good idea?

Otherwise I am brushing and vacuuming and backwashing.

Pump is staying on.

[Watermom]

It was fine to put a tab in the skimmer since your CYA is low. Just make sure the pump doesn't go off for more than 8 hours. Also, do not add other ingredients on top of that tab.

Good decision to get the kit.