returning algae

[pool idiot]

We have had a pool for over 4 years now and have had very few difficulties until now. Last week the pool started cloudy and everyday got worse until green, unable to even see the bottom. Took samples to store and adjusted water as advised, same, took more water for samples and told that the chemicals were all withen range. Bought Algaecide and shocked the heck out of the pool. We wre told we needed a new filter so several hundred dollars later the pool was clear. That only lasted a few days and now we are back to nast green. The chlorine level was fine this morning.
Any advice would be appreciated.

Thanks

[mr_clean]

can you show chemical reading?
how many hours a day are you running filter?

[Guest]

Sorry I didn't respond sooner, here is the info Leslies gave us.

FAC 5+
TAC 5+
PH 7.2
TA 120
Calcium hardness 330

They also advised us to drain the pool 3/4 and start over.

[pool idiot]

--------------------------------------------------------------------------------

Sorry I didn't respond sooner, here is the info Leslies gave us.

FAC 5+
TAC 5+
PH 7.2
TA 120
Calcium hardness 330

They also advised us to drain the pool 3/4 and start over.

[mr_clean]

do you know what your CYA level is?
This helps knowing, if CYA is 100 or above it makes chlorine less effective and if no CYA then chlorine will not be protected from sun. A good level is 60-80. Remember if you use chlorine tabs they have CYA in them and normally you need to check CYA level more so it does not rise to high.

When shocking pool you want chlorine level above 20ppm, checking it 2-3 times a day adding liquid chlorine to boost back up until water is clear. Run filter 24/7 until clear, depending on size of cartridge filter you may need to remove and clean. when all is clear & clean, clean filter with filter cleaner.