Trying to SLAM - bleach not responding as thought

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
20,152
Laughlin, NV
Before adding CYA -- please do this:
Raise your FC in the water using enough liquid chlorine to get to 10 ppm using PoolMath. Circulate the pool for 15 minutes. Test FC and CC. Report the numbers here.
 

jamie973

Active member
Jun 14, 2019
41
New Jersey
thanks for the heads up Deb - not too close to one - but I know where they are now.

I just added 363 fl oz at 6% - which according to the pool calculator should have raised FC by 8.8 - it's now at 3.4. We did have rain last night. Keep bleaching?
 

justinc

Gold Supporter
Apr 3, 2019
585
Texas
thanks for the heads up Deb - not too close to one - but I know where they are now.

I just added 363 fl oz at 6% - which according to the pool calculator should have raised FC by 8.8 - it's now at 3.4. We did have rain last night. Keep bleaching?
Marty (@mknauss ) posted up above he wanted you to do the ammonia test. Add 6.6ppm more on top of your 3.4ppm to get you to 10, circulate, test again, and post your results here. Make sure to also test for combined chlorine and post that result as well.
 

jamie973

Active member
Jun 14, 2019
41
New Jersey
ammonia test? I didn't see where that was mentioned.

In the meantime - am I doing this right - 2 more 121 fl oz bottles should raise FC by 5.8. so I should be close at that point - is this correct? CC is at 1.

My first results were a bit off - multiplied by .2 instead of .5 So numbers from June 14 were 1FC and .5CC
 

justinc

Gold Supporter
Apr 3, 2019
585
Texas
He did not spell out that he was concerned about ammonia, but the procedure he asked you to do is typically referenced on this forum as a way to see if you have ammonia. The concern rose out of the fact that you had CYA in the water (or thought you did) and then reported it had dropped to 0. This raised his concern that you may have a special case where over winter without sufficient chlorine in the water bacteria can take hold and actually EAT the CYA. The byproduct is large amounts of ammonia. When chlorine is added to the pool, it all immediately gets bound up to the ammonia (chloramines / combined chlorine = chlorine + ammonia). This was a possible explanation as to why you were noticing that when you added bleach to the pool you weren't seeing the expected rise in free chlorine. However, since you are reporting a combined chlorine of 1 then I think the concern is not that you have ammonia but that you simply have organics in the water (algae, gunk) that are eating up your chlorine pretty quickly. Your loss of CYA may be attributed to something else (lots of rain or water exchange over winter, etc). Anyway, I would say proceed to full SLAM at this point. You may find yourself checking and adjusting chlorine frequently in the beginning.
 

DorsalSpine

Silver Supporter
Jul 8, 2013
361
Columbus, Ohio
The goal is to raise your FC, test, wait an hour or so for it to circulate and test again. Both readings should be the same or very close. The sun might burn some off while you wait. If the chlorine level holds you do not have ammonia in the water. If you don't have ammonia it is safe to add CYA and start balancing your water.

If you have ammonia you don't want to add CYA since that will make it worse.
 

IceShadow

Gold Supporter
Jun 8, 2019
628
Milwaukee, WI
ok, looks like I'm at 11 FC and .5 CC
Test again in like 20 minutes and let us know the results - if ammonia is present FC will drop a ton and CC will be higher. If that's the case you have to deal with that before adding CYA.

If it stays somewhat close or FC only drops a little while CC stays very low, then you're good to add CYA.
 

IceShadow

Gold Supporter
Jun 8, 2019
628
Milwaukee, WI
Pool Time 5 lb. Chlorine Stabilizer-23517PTM - The Home Depot if you get at Home Depot.

I put some in a mesh bag and hung it in front of the return jets off a pole with a weight on the back end of it to keep it in place. You can also use a stocking or even a normal sock. Squeeze every so often to assist with water changeout in the sock/etc. and it will dissolve faster but still might take a day or two.

Apparently CYA tests might not show the increase for 48 hours, as a heads-up! But you can up your FC to assume it's in there right away.
 

IceShadow

Gold Supporter
Jun 8, 2019
628
Milwaukee, WI
The pool stores just charge more but the chemicals are sound. I still get liquid chlorine at a pool store because they sell 4 gal 12.5% for $14.50 + tax, which isn't bad.

If a home depot near you has some of what I linked above you get 5 lbs for $21. The link you had was 4 lbs for $30. The HD stuff is cheaper, but if $9 isn't a big deal you can go ahead and buy at the pool store.

(I didn't have a HD near me last night and went to the pool store and spent $16 on 2 lbs - but I only needed 2 lbs so it worked out anyway.)
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
22,049
San Dimas, CA (LA County)
Is there something generic that I can get for it - it should I get something like this at Leslie's - I know people cringe when they hear pool store.
Go to any big box or hardware store that has a pool section and they will sell stabilizer and I'm pretty confident it will be cheaper than Leslies. You also won't get the scare tactics and you're wallet won't be so light when you leave.

It's all the same chemical. Salt is salt is salt and baking soda is baking soda is baking soda and CYA is CYA is CYA no matter who sells it or how fancy the packaging is. Home Depot $21 for 5 lbs, Leslies $30 for 4 -- on sale!
 

IceShadow

Gold Supporter
Jun 8, 2019
628
Milwaukee, WI
I just added to my 20k gal pool yesterday, 2 lbs was about 10 ppm CYA. You don't want to overshoot because you can't remove CYA once it's added without a drain/refill. So, I'd say the 4lb should be fine, maybe only add 2lb, give it a couple of days, test, then add more if needed.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
20,152
Laughlin, NV
You will want a minimum of 30 ppm CYA in the pool water, likely 40 or 50 ppm would be better.

Get two packages of it if they are 4 lbs each. 4 lbs will put 24 ppm CYA in your pool of 20000 gallons.