DE Filter - backwashing too many times?

ayc01

New member
Jun 2, 2024
4
Huntington, NY
Pool Size
36000
Surface
Plaster
Chlorine
Liquid Chlorine
Hi all - wished I knew about this forum before frequenting the pool store.

Have:
DE4820 Filter
Gunite pool (36,000 gallons)

Status:
Pool chemistry levels as of yesterdays is acceptable except CYA (none) so store associate guided me to purchasing 3x 4lb conditioner /stabilizer.

Problem:
I cannot backwash for 48 hours when I pour these into the 2 skimmers. Currently I am backwashing between 3-5 hours. They say I may have a phosphate problem and I should come back after 1 day (after adding in calcium and alkalinity).

Question:
1) Do I wait until my filter stays on consistently at 10-18psi (green line) for at least 24hrs?
2) Any other way to get CYA up?
Redline is at 20psi and the jets struggle, that's when I backwash. I generally put in around 1-2lbs of DE after each backwash.
The pool has gotten better clarity in a week's time, but it started it out as backwashing every 45 min - 1 hour or so to now 4 - 5 hours. Attached pictures for reference .
3) Am I doing something wrong here?

Background:
Since pool opening I've already went through 25lb of DE due to backwashing and 10 bags of shock (had to repair pump gaskets so had still water for 10 days in between opening and now).
Pool was unused and closed for 2 seasons. Had it power vac 2 days ago when we could see the bottom of the deep end.
We contract a local family owned pool co to open and close our pool so I assume they have cleaned our filter and added the original 4lbs of DE at the start.
 

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Hi all - wished I knew about this forum before frequenting the pool store.

Have:
DE4820 Filter
Gunite pool (36,000 gallons)

Status:
Pool chemistry levels as of yesterdays is acceptable except CYA (none) so store associate guided me to purchasing 3x 4lb conditioner /stabilizer.

Problem:
I cannot backwash for 48 hours when I pour these into the 2 skimmers. Currently I am backwashing between 3-5 hours. They say I may have a phosphate problem and I should come back after 1 day (after adding in calcium and alkalinity).

Question:
1) Do I wait until my filter stays on consistently at 10-18psi (green line) for at least 24hrs?
2) Any other way to get CYA up?
Redline is at 20psi and the jets struggle, that's when I backwash. I generally put in around 1-2lbs of DE after each backwash.
The pool has gotten better clarity in a week's time, but it started it out as backwashing every 45 min - 1 hour or so to now 4 - 5 hours. Attached pictures for reference .
3) Am I doing something wrong here?

Background:
Since pool opening I've already went through 25lb of DE due to backwashing and 10 bags of shock (had to repair pump gaskets so had still water for 10 days in between opening and now).
Pool was unused and closed for 2 seasons. Had it power vac 2 days ago when we could see the bottom of the deep end.
We contract a local family owned pool co to open and close our pool so I assume they have cleaned our filter and added the original 4lbs of DE at the start.
To answer your question directly: yes theres another way to raise CYA. Dont put it in the skimmer. Put it in a sock and hang it in front of a pool return. In general, dont put any chemical in the skimmer.

But I’d not be doing my job if I didnt warn you about pool stores and how bad they are at testing water accurately, especially the CYA. Sometimes they tell you its way higher than it is. You would be far better off financially if you never got another test there again and your pool would look better as well. Get your own test kit, the TF-100 is good. Green algae like that is from under chlorination which means your chemistry is not acceptable and no amount of filtering with kill algae.

 
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To answer your question directly: yes theres another way to raise CYA. Dont put it in the skimmer. Put it in a sock and hang it in front of a pool return. In general, dont put any chemical in the skimmer.

But I’d not be doing my job if I didnt warn you about pool stores and how bad they are at testing water accurately, especially the CYA. Sometimes they tell you its way higher than it is. You would be far better off financially if you never got another test there again and your pool would look better as well. Get your own test kit, the TF-100 is good. Green algae like that is from under chlorination which means your chemistry is not acceptable and no amount of filtering with kill algae.

Thank you, doing it on the return!
Will buy those test strips
 
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