Help!!! What is this and how do I get rid of it

[jlg144]

Photos attached. Appears to be grayish to tan in color.
Keeps coming back even when water is balanced
20000 gallon above ground pool cartridge filter - new filter
Cya 59

we had a cya of 110 so we have drained and filled to get it to 59
before we start treating this I was hoping you could help us identify what it is and a course of action
its spread pretty evenly along the pool the whole pool bottom. Collects in center and liner seems most
None on the walls does not feel slimy. Water appears clear
Cant seem to vacume it out even with sock filter. And robot with filter down to 2 microns

Did two algae treatments one when cya was high and one when we got it down.
Now using unstabalized shock and tablets.

 

[Texas Splash]

Even with the pics, it's a bit difficult to tell at the moment what you have there. You mentioned the water is balanced? It would be best to see those test results from your TF-100 or Taylor K-2006. That would help us to confirm (or rule-out) probable causes. Can you also confirm for us if you are using that Aqua Smart system?

 

[jlg144]

Even with the pics, it's a bit difficult to tell at the moment what you have there. You mentioned the water is balanced? It would be best to see those test results from your TF-100 or Taylor K-2006. That would help us to confirm (or rule-out) probable causes. Can you also confirm for us if you are using that Aqua Smart system?

Thanks for responding so quickly. This problem has been going on since we opened the pool May 1st.
Thats when we got the k2006 and discovered the CYA problem. So we began to drain and fill over the next couple weeks.

We got it balance week before last and did the algae treatment. Then went on vacation last week and just returned from vacation last night. It was balanced when we left and we shocked and put 3 unstabalized tabs in before we left and pool perfect with phos free.

This morning the chlorine was at .5. I put in liquid chlorine to get the levels back up. I will give that a couple of hours and do a full test with the k-2006 and post.

This season we swapped to the pool RX system.

 

[jlg144]

Thanks for responding so quickly. This problem has been going on since we opened the pool May 1st.
Thats when we got the k2006 and discovered the CYA problem. So we began to drain and fill over the next couple weeks.

We got it balance week before last and did the algae treatment. Then went on vacation last week and just returned from vacation last night. It was balanced when we left and we shocked and put 3 unstabalized tabs in before we left and pool perfect with phos free.

This morning the chlorine was at .5. I put in liquid chlorine to get the levels back up. I will give that a couple of hours and do a full test with the k-2006 and post.

This season we swapped to the pool RX system.

ok just finished test with k2006 vacuumed two cycles with bot filters down to two microns will post pics when bot finishes

FC. 4.2
CC. .6
PH. Between 7.6 and 7.8
TA. 90
CH 180
CYA. 50

i will test again at 8pm and conduct OCLT test.

 

[jlg144]

I ran the bot two consecutive cycles. Two hours per cycle. Then took it out and these photos are of the bags. Filters down to 2 microns

 

[Jezza]

Yes confirm what is going on with an OCLT. Use the 10ml sample for your FAS DPD testing where each drop is 0.5 (rather than 0.2)- it will save you a stack in the 0871 reagent. If you need to SLAM, you are going to need to order some more of the 0871, possibly more of the 0870 powder and while your at it some more of the CYA
R-0013 as the amounts in the K2006 are nowhere near enough.

 

[jlg144]

Tested tonight and FC - 4.5, CC - .5 Removed unstabalized tab from skimmer.
Will advise test results tomorrow morning.

 

[jlg144]

Pool floor is 70% better this morning. Previous mornings after vaccuming all of it would be back.
So running The bot two back to back cycles must be better than just running one cycle as we previously have.
The bot is in now for another round. Then I will brush the whole pool.

OCLT results.

Loss of .5

FC - 4
CC -.5
PH - 7.8
TA - 90

 

[Texas Splash]

Passing the OCLT is fantastic. You may be on the verge of clearing-up whatever was in there. I would recommend increasing FC a little more to about 6-7 since 6 is your ideal target range based on your current CYA - never below 4. There should be no need to waste money on the pool store treatments like Pool Prefect and stuff. None of those algae/phosphate removers resolve the true issue of proper sanitation that is managed by chlorine itself. Save your money for more important things.

If you have any questions down the road, the vital links you see below in my signature will serve you well. Have a great day.