Green pool …tried everything (i think) still green

[Lisa ram]

Hello all… newbie here. We purchased a home with an inground pool. (21k gal, DE Hayward filter) Didn’t have a cover over the winter. Naturally, water was green and pond like. We got to work after reading through some threads here. We scooped lots debris, we vacuumed scooped some more, ran our robotic vacuum as well. Decided our best bet would be to SLAM the pool. Tested the water (Taylor k2006)
FC- 0
PH 8
TA 88
CH 80
CYA 5
So we added 5lbs of shock. Ran pump for 24 hours. Water is no longer dark green but almost a milky green now. Our readings now are:
FC- 0
PH 7
TA 60
CH 80
CYA 6

What am I doing wrong? Also, opened up the filter to rinse away all algae from the grid.

Any help will be greatly appreciated. Thank you in advance.

 

[Mdragger88]

You’re on the right track - sorta.

Read this article & follow it exactly

SLAM Process
It is to be done with liquid chlorine,
A starting cya of 30ppm so the sun doesn’t eat all your fc
(Put granular stabilizer in a sock in front of a return for this)

&
starting ph of 7.2 (point your jets up so the aeration increases your ph a little)
You then raise your fc to slam level for your cya FC/CYA Levels & MAINTAIN that multiple times per day until u pass ALL 3 end of slam criteria.
The more often u test & replenish fc the faster u will meet all 3 end of slam criteria. Every couple hours is best.
Use PoolMath to calculate amounts.
How are u getting a cya of 6?
What “shock” did u add?

 

[Mdragger88]

Also you will need to backwash your filter when pressure rises 25% over clean pressure. This may happen often with a DE filter since they catch everything & fill up quickly so keep an eye on it.

 

[IceShadow]

Some of your numbers don’t make sense. The Taylor kit can’t measure a CYA of 5 or 6, or a TA of 88. How are you getting those numbers?

 

[Strawberryshortcake]

Was that the only addition of chlorine, the 5lbs? Was it all at once? Was it powdered? Cal-hypo?

If you added 5lbs of 65% cal hypo all at once that was 18ppm FC...
If your pool has 0 CYA (5 and 6 are not an accurate reading), your SLAM level is only 10. So you added too much. You don't want to go over the appropriate level for your CYA or you risk damaging the pool, your equipment/liner. It does not clear the pool up faster and it just burns off, wasted.

You shouldn't be getting a CYA of 5 or 6 so that tells me you are likely preforming the test wrong. Can you tell us how you're doing it?
This time of year you really need at least 30 CYA to protect the chlorine from the sun.
Did you test CCs? It comes after the chlorine powder test.