Working on a SLAM

dd564

Active member
Mar 15, 2016
28
Shakopee
First time I've had my water get cloudy. I think I had my chlorinator set to low and something starting growing.

Anyway, wife noticed water was cloudy when she opened the pool. I bought 3-4 gallons of bleach threw them in and left it for several hours and FC was zero.
Tried it again with 5 gallons later. Same result. Chlorine was gone as fast I was putting it in.

Tossed in enough gallons which should get my FC to about 20.

I've added CYA which should get me around 30 CYA, but haven't tested while it dissolves.

Water started to clear up. (I could see my tool brush about 1.5 feet deep. Then 3 feet. Then 5 feet. Etc.

Finally read about SLAM yesterday. Went and got FC up to 20 and it wasn't immediately gone.
Woke up this morning and FC was down to 1.5.
Bought a ton of bleach and went at it again.
Dumped in 8 gallons of 6.5 bleach to get it to about 20 at 8:50 AM.
Water test at 10:50. FC:12
Added 3 gallons to get me about 19-20 FC (didn't test)
Water test at 12:50. FC: 14
Added 3 gallons to get to 20.
Water test at 2:40. FC: 15
Added 2 gallons
Water test at 4:40. FC to 12:5
Added 2 gallons
Water test at 6:40. FC to 15
Added my last 3 gallons.

I can see the bottom now, but still cloudy, but much better.
But I'm concerned at the rate I'm still losing FC that I'll be at 0 or 1.5 tomorrow morning.
I have my chlorinator running as well during this time to "help".

Seems like I'm going through a lot of bleach!

It's dark and I have the pool cover open and am vacuuming.
 

HermanTX

Gold Supporter
May 20, 2020
2,640
Katy TX
Pool Size
14600
Surface
Plaster
Chlorine
Liquid Chlorine
You are doing all the right things. Sometimes it just takes more time.
Testing every 2-3 hrs is great. Maybe test before you go to bed and add LC to reach your SLAM level to get you through the night.

One point is that you have never confirmed your CYA. You only stated you added stabilizer to get to 30ppm which implies you were significantly low on CYA before which may be why you started to see cloudiness and algaeIf you had very low FC as well.

It does appear you are using a lot of LC but you also have a large volume. Your SLAM level should be 40% of your CYA level so that really needs to be verified.
Are you vacuuming or backwashing your filter? You are brushing which is keeping it stirred up so it should be captured by the filter Or vacuum to waste.
 

dd564

Active member
Mar 15, 2016
28
Shakopee
Did a vacuum last night. Have been backwashing.

Last check last night was FC: 12.5
Added to bring it around 20.

This morning checked.
12 hours later was at 7.5 so I was glad to see it didn't disappear completely.
Seems like I'm dropping 1 ppm an hour instead of the higher rate from yesterday which was around 7.5 per hour.

Still need to check CYA.
 

PoolStored

Gold Supporter
Jun 24, 2021
566
Ashtabula, OH
Pool Size
31000
Surface
Vinyl
Chlorine
Liquid Chlorine
You are losing so much FC, because you don't have any CYA (low level) in the pool, and you are raising your FC way beyond the SLAM level (causing the high consumption), assuming CYA of 30. Stop adding to target 20 FC. FC above slam level can damage the liner.

PLEASE READ:
SLAM Process
FC/CYA Chart

On the FC/CYA chart, click on *SLAM* and you will see your target FC for SLAM at 30 CYA is FC = 12.

*PLEASE* test your CYA level, and adjust your target FC according to the FC/CYA SLAM level. You will lose less FC, you won't damage your pool, and will use less chlorine.

*ALSO: DO NOT SWIM AT FC LEVELS ABOVE SLAM FC FOR YOUR CYA. IT IS NOT SAFE.*

Are you using PoolMath? If so, can you share your logs? Thanks!
 
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