First time using the SLAM approach. Am I on the right track?

Jump to latest Follow Reply
E

ethyloh

0
Jul 9, 2015
13
MA
I have a 33,000 gallon 20x40 pool with a 275lb sand filter (I just changed the sand).

I've owned the house for a while, and when I open it each summer, I usually just dump a bunch of chlorine in every night until it clears (usually takes 2 weeks).

This year, I've decided to do it right, so I bought a K-2006 test kit.



I took the cover off this afternoon and it was black. pH was way over 8, so I added acid to drop the pH to 7.2 - 7.4.

Then I added 54oz of Leslie's Power Powder Pro (73% available chlorine, no stabilizer). I intend to switch over to liquid chlorine, but I have about 50lbs of this left from last summer.

After 1 hour:

FC = 0.8ppm
CC = 0.8ppm

I assume I need to add more chlorine already, correct?

Thanks
 
Yes, you are correct - need more chlorine. During a SLAM, you will likely find that you need to add chlorine several times each day.

When you get a chance, please post a full suite of test results. You need to be sure you are dosing chlorine to the SLAM level according to the pool's CYA. Also, you need to keep an eye on the CH level. The Power Powder Pro is a calcium hypochlorite form of chlorine which will add calcium with every dose.
 
BoDarville said:
Yes, you are correct - need more chlorine. During a SLAM, you will likely find that you need to add chlorine several times each day.

When you get a chance, please post a full suite of test results. You need to be sure you are dosing chlorine to the SLAM level according to the pool's CYA. Also, you need to keep an eye on the CH level. The Power Powder Pro is a calcium hypochlorite form of chlorine which will add calcium with every dose.
Click to expand...

I haven't had the chance to test everything, but I will. My neighbors must think I'm crazy for cleaning the pool at 1AM.

I added another 3 cups of chlorine. FC is now 6ppm, and CC is 0.6ppm.



With respect to stabilizer, I specifically don't use the stabilized chlorine, so I'll bet my CYA is very low or non-existent. pH swings are also possible, as I haven't buffered the water yet.

Admittedly I'm a little unprepared since I got out of work late. I'll have a chance to go to Leslies or Namco tomorrow night.

In the meantime, any reason I can't add a few of the stabilized chlorine pucks? Those maintain the FC levels in a pinch.
 
Sooooo....

Did Taylor change the CYA test?

I just tried to do the test according to the instructions with the kit.

However, the sample tube provided in the kit does not have a black dot at the bottom.
 
So it's been 2.5 days since I opened the pool.

It went from black disgusting water to completely blue water (albeit still extremely cloudy).

I can see the dark spots on the bottom of the deep end where there is some sediment.

I've been shocking the pool at night to about 12ppm FC. I also keep 4 tabs of trichlor in the pool to add a little stabilizer (since I can't do my CYA test until Taylor sends me a comparator with the black dot on the bottom).

It has been nothing but bright sunshine for the past week, and my pool still has about 2ppm FC (0.8ppm CC) when I test it the next night.

I've been keeping my pH at 7.2-7.4. It's a vinyl liner, so I'm not overly concerned with calcium hardness.

So now is it a waiting game until it's crystal clear?
 
Ok so it's day 12 in my effort to clean the pool. I've been following the slam procedure and have a nice blue pool. I can see the drain in the deep end, but the water is still slightly cloudy.

I've been keeping FC around 11, and when it drops to 5 or so, I bring it back up to 11. CC is around 0.6 - 0.8.

I increased TA from 70ppm to 90 ppm (which definitely makes the water have that nice smooth and shimmery appearance, which I love). It also buffers the pool perfectly, as I get very little pH change after shocking with chlorine. My pH stays around 7.2-7.4.

Calcium hardness is 500ppm, which is a direct result of using the remaining calcium hypo (~40lbs) from last year. I have since switched to sodium hypo in the bottles. My pool is vinyl lined, so I'm not too concerned.

CYA is around 10-20ppm based on an estimate with the defective sample tube in my K-2006 (since Taylor has not yet sent me the replacement with the black dot). I chlorinate in the evenings, so I'm not too worried at this point.

I've been running my Kreepy Krawly most of the day, so there is nothing on the bottom of the pool.



All this brings me to the following question...

The levels in my pool are exactly where they should be. FC levels are consistently high. There is no visible sediment on the bottom of the pool. The water is cloudy, but I expect it to turn crystal clear in the next couple of days. It is 90+ plus degrees outside, with bright beating sun. The pool is exceptionally warm and inviting. I only have another day off before returning to the daily grind.

Is it really a big deal if I jump in the pool with the way that it is right now? It's definitely cleaner than any lake I've ever been in, and I'm still here.

Can I go for a swim or not?

IMG_20160704_162550271.jpg
 

Enjoying this content?

Support TFP with a donation.

Give Support
Fyi, high CH is a problem for vinyl pools, just like any pool. It is low CH that vinyl does not care about. Your CH is now high enough you need to keep tight control on your TA and pH to avoid calcium scaling.
 
jblizzle said:
Fyi, high CH is a problem for vinyl pools, just like any pool. It is low CH that vinyl does not care about. Your CH is now high enough you need to keep tight control on your TA and pH to avoid calcium scaling.
Click to expand...

Right. I've been backwashing so much that I need to keep adding water, which should reduce the Ca2+. I also switched to the Na+ hypo, so no more calcium should be introduced.

- - - Updated - - -

AimeeH said:
Do you yet know your CYA number?

The main reason NOT to swim would be FC that high with too little CYA. That might be rather harsh. You'd want at least 20-30 ppm cya.
Click to expand...


The test vials that came with my K-2006 did not included the black dot. I contacted Taylor over a week ago, and they said they'll send a proper replacement (which still hasn't shown up). In the meantime, I've been placing the vial over a black dot on a piece of paper to act as a very rough approximate of the test. My CYA is 10-20 ppm at best.

For the record, years ago I used to jump in the pool immediately after shocking it with granular to help mix the chlorine in the pool. The high FC levels didn't seem to bother me at all. :eek:
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply