SWG - No FC???

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Went to a different LPS to get liquid chlorine and had them test for Darns and giggles. Their test were pretty close to mine and the other LPS. Same high phosphates, although surprisingly they said to not worry about it. CYA measured at 21 vs other LPS was at 22 and I'm getting a full vial and still able to see the dot. Maybe those numbers are right, unless there is any way either the phosphates or the amount of metal remover products I have added could somehow interfere with the CYA test.
 
I'm steady at FC 13 after 2.5 gallons and the SWG cranked to 100% since about 9am (it's now 4:30pm).

How long at a high FC before you typically see metals settle out and turn the water brown? I think the last time we had brown water was within minutes of adding liquid, but that was before any sequestrant was in the water. One other time more recently was overnight when I set the SWG to "shock".
 
10:10pm. FC - 8. Dropped 5ppm in 5 hrs 40 mins while covered by the auto cover and thus not exposed to any sunlight. With the SWG at 100%. That seems, significant. Water is still very clear, no cloudy, no algae and no brown iron color.

Added 1/2 gallon
 
7am. FC -9. Added half gallon. Still darn clear. Pressure still good too. I’m really quite surprised and a bit dumbfounded that it’s not brown.

question for the OCLT during SLAM, does the high chlorine result in clorone loss on its own? Or should it hold at 12ppm overnight?
 
Separate question... I have received conflicting information regarding recharging my DE filter. It requires 6 lbs of DE. Some of the LPS / pool guy people have said after each backwash, add the full 6 lbs. Others said add 3 maybe lbs because you won't get all of the old DE out during a backwash. The later makes sense so that's what I've been doing. What is the right answer?

I'm also thinking after all of this, and all the iron issues, that I should open it up and wash off the DE completely to ensure any old DE with old algae or iron particles trapped inside are completely gone.
 
RookWDW said:
question for the OCLT during SLAM, does the high chlorine result in clorone loss on its own? Or should it hold at 12ppm overnight?
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Once you do your last FC test before bed, assuming the chlorine had time to mix for about 30 minutes, it should hold well until morning with no sun on the water. That's whay the 1 ppm drop allowance is considered acceptable.

RookWDW said:
I have received conflicting information regarding recharging my DE filter. It requires 6 lbs of DE. Some of the LPS / pool guy people have said after each backwash, add the full 6 lbs. Others said add 3 maybe lbs because you won't get all of the old DE out during a backwash. The later makes sense so that's what I've been doing. What is the right answer?
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I would agree with you, the later. Backwashing does not remove all previous DE.
 
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My unknown CYA issues (could be 20, could be 40) should not be having any effect on the chlorine loss so long as I keep it covered and it is not getting sunlight, right? CYA only helps stabilize chlorine loss due to breakdown from the sun?
 
RookWDW said:
My unknown CYA issues (could be 20, could be 40) should not be having any effect on the chlorine loss so long as I keep it covered and it is not getting sunlight, right?
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Not necessarily. If someone was to over-shoot their FC level because of a much lower CYA, then there's not enough stabilizer for the chlorine to adhere to. Maybe not as critical between a CYA of 30 or 40 (FC 12 or 16), but if the CYA is 20 or lower it could influence the OLCT. A minimum CYA of 30 is a must.
 
I had the pool guy that installed the SWG out to inspect the SWG and ensure it is actually working. He took it off and did a "bucket test" and showed that it was producing chlorine and other than minor calcium build up was functioning properly. I asked him to measure and estimate pool volume and he came up with 25,900 (36.5x18 - depth of 3'; 5.5' and 7.5'). He also tested the water using the taylor kit they use and said CYA was negligible in that there is definitely sum but less than 20.

I'm struggling to understand the CYA and won't add any until my new kit arrives on Thursday. I'm sure I added 8 lbs. I have had to add a decent amount of water, maybe a combined 4 -6 inches as I've had to backwash like crazy due to the iron issues. But that is now myself, two different LPS using their electronic kits, and the pool guy all finding results at 20 or less.

Had to backwash again and I'm adding a bit more top off water (and another gallon of liquid). Backwash is brown and chunky and I run backwash-rinse-back-rinse-back-rinse-filter before it is relatively clear.
 

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For me personally I have had great success using my Taylor test kit we recommend here as well as my local pool supply company. I have to test each month and keep a print out from a certified dealer to keep my Pebble-tec warranty in tact. Each time I have tested they have been spot on with my own results. So dont totally discount the pool supply stores until you find out for yourself.
 
I'm not beating myself up yet. Actually, this difficulty is making me more confident in handling this pool.

Reading and more reading and I see this topic has been discussed here many times. PoolGeek a few times mentioned that certain bacteria found in biofilms can consume CYA. Yikes. We twice had the pool closed for a couple days due to crud weather, opened the pool to a slight cloudy pool and to find the liner covered in a clear slimy film. Maybe that is my connection.

From poolgeek:

Unless the bacteria were in biofilms, say in your sand filter, it is unlikely that there were living bacteria eating the CYA since it takes a very low level of chlorine to kill most bacteria. Nevertheless, it is certainly possible to have some channeling in a sand filter such that bacteria aren't exposed to very much chlorine, then form biofilms, and can then grow relatively protected and could convert CYA into ammonia (i.e. use the CYA as a lovely source of nitrogen) more slowly than in a pool with no chlorine at all. This is just speculation, but your approach to shock the pool is part of the solution. The other would be to check the sand filter for channeling and fix it as needed (see this Pool School article).
 
Okay. 3:30 and FC at 8.5.

7am was FC - 8 added half gallon
about 8:15 pool guy test said FC - 9 (pool was open to sun for about an hour)
9:30/10am backwashed, added an inch of new water, added a gallon
11:30 -FC 13.
3:30 - FC back to 8.5. - added a half gallon

Sigh.
 
Yes, but it was open for about an hour, and it was hot and sunny, and I added a half inch to an inch of water. I wonder about the DE filter holding something nasty. The skimmer looks clean. Maybe under the cover of the bottom drain? But, shouldn't the FC kill that algae?
 
How am I supposed to check that? Close halfway and go for a swim? Can I go in with 12 ppm FC? Also, how would I even clean that? Would I need to have the entire cover removed and opened? That would be expensive.
 
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