2nd time SLAM - help me do better this time!

[Pool-in-the-Hills]

Hi all,

Thanks to TFP, our pool opening went better than ever (although, I SLAMmed a smidge/alot too long). My FC level has been 0 the past couple of days, but the pool is clear, so I am SLAMming again. Help me get this right!

Here are the starting numbers on 6/11:
FC=0
TA=160
pH=8.2
CH=200
CYA=30

At first, I thought I had a TA issue (only), so I added 4 cups pH Down on 6/14, which brought the TA down to 140, pH 7.2; then (later), I added 3 c LC 10%. The next day TA was up to 150 and FC=0. I jumped on TFP and smacked my forehead - time to SLAM!

SLAM FC target is 12. So, at noon today (after buying LC!) I added 7 cups of LC 10% and brushed the entire pool. Pool robot is on continually. At 1 pm, FC=2. I added another 7 cups of LC 10%. At 2 pm, FC=3. I backwashed for 3 minutes, then added 8 cups of LC 10%. At 3 pm, FC=4.5. I added 8 cups of LC 10%.

Do I keep doing this until FC=12, then hold until overnight chlorine loss test is [whatever it says on Pool Math (I forgot)]? Again, the pool is clear and the backwash is pretty clear, too. It's been in the 60's-70's every day, sunny, cool nights.

Thanks!

 

[Newdude]

10% and brushed the entire pool. Pool robot is on continually. At 1 pm, FC=2. I added another 7 cups of LC 10%. At 2 pm, FC=3. I backwashed for 3 minutes, then added 8 cups of LC 10%. At 3 pm, FC=4.5. I added 8 cups of LC 10%.

This ^^^^^. This is how you win. Hit it hard and often. The first day or two need every 2 hours and it will stretch to 4…. Then 6….. then 12. By day 3 you can resume normal life with 3 tests/corrections. M is for maintain and they ain’t kidding. Anytime below SLAM target looses efficiency and sets you back. Well done so far. Don’t forget to verify you reached the target each time you add after it circulates for 20 mins.

With clear water you can perform Overnight Chlorine Loss Test each night, because that’s the first sign it’s time for the overnight test. If your FC is still dropping quickly, you’ll probably fail the first one or 3, but you’re close at least.

The OCLT takes the sun/UV out of the equation so the water by itself should not loose any FC. If it looses more than 1 with no sun, you still have algae being killed. Also you need the CC’s to be .5 or less. Some of both of those is testing error because nothing is perfect, and the rest is ok if it’s just a little as there is always something being sanitized in the pool.

In the meantime, you need to brush and vac as much as possible. Once a day is bare minimum. 2-3 will help speed it along.

Keep an eye on the filter and clean at a rise of 25% PSI.

You got this.

 

[Pool-in-the-Hills]

Don’t forget to verify you reached the target each time you add after it circulates for 20 mins.

Thank you for your encouragement!!

One question - 20 minutes after I add LC, I should test to make sure I am at FC=12? I have just been adding and testing after an hour, then adding LC if test is not FC=12. At that 20 minute mark, if it is above FC=12, then I have added too much; if below, then I have added too little. Correct?

By the way, at 4 pm FC=7.5 (added 8 cups LC), 5 pm FC=9.5 (added 8 cups LC). I'll go check now, as it's been 20 minutes, and if it is 12, then I will wait a couple of hours before I check again.

 

[Newdude]

One question - 20 minutes after I add LC, I should test to make sure I am at FC=12?

Yes. You are just looking to verify the added bleach was good. You’d be surprised how often 2 jugs give different results. So you verify you hit your 12, instead of just *thinking* you did.

I have just been adding and testing after an hour, then adding LC if test is not FC=12

You’re basically doing the same thing, or achieving the same end result at least. Go to 2 hour testing, verify, and enjoy some break time.

if it is above FC=12, then I have added too much; if below, then I have added too little. Correct?

Correct. Or the bleach want quite full strength. Don’t worry if you are a few PPM over. You’ll waste a little but not a big deal at all. If you are low, add enough to hit the target.

Thank you for your encouragement!!

Anytime. We are always here. Ask away no matter how silly you think it is, especially if you are unsure of anything. Ask, test, do. Verify.

If you just blindly act, you’ll create new problems, which we will help you with also, but we’d rather have the silly question and only the original problem. For your sake.

 

[Pool-in-the-Hills]

I performed the overnight test late Friday night/early Saturday morning - FC=12.5 both times and CC=0.5! Woo hoo! Thanks, again!