SLAM - can't pass overnight test

[Sivartb000]

Hey guys,

I messed up and didn't add chlorine for a couple days, and as a result I got an algae bloom.

I started treating it on Monday, got it clear and below .5 CC by Wednesday but the last two mornings I've had a 1.5 - 2ppm drop in FC over night (testing at 8:30pm and then again at 6:30/7:00am the next morning - no direct sunlight during those times).

My questions: 1) Is a 2ppm overnight drop acceptable - or is 1ppm a hard fast no exception rule? 2) Would I be ok to allow FC to drop to safe swim levels for the weekend and resume next week - or will I pretty much lose all SLAM progress? 3) Would I be ok to drop FC to safe swim levels, and will the kids be safe swimming? 4) What is an absolute highest FC you'd let kids swim who may swallow a little bit of water (I have a 5 year old and a 18 month old - water inevitably gets in their mouth, no amount of telling them not to do that seems to stop them - though theyre not drinking it by the glass full).

FC: No lower than 12 (I get it up to about 18 before I leave work, because I can't check it until I get back home at 6pm, and its between 12 - 14 when I get home)
CC: <0.5
CYA: 30
PH: 7.7 (have been keeping it between 7.4 and 8 the whole process - my jet points up and causes a lot of aeration, so my PH gets high quickly running the pump 24/7)
TA: 100

 

[Donldson]

1: Hard and fast rule, you still have something in the water
2: It is safe to swim up to SLAM level as long as you can see the bottom. If you have concerns get in and see if you can tell the FC is elevated, you will be pleasantly surprised.
3: See #2
4: Also see #2, though if the kids are getting more than a couple gulps then it's not unreasonable to want to drop it a bit

If you are concerned you can allow it to drop down in to the "Target Range", but you definitely want to keep the SLAM up afterwards. Something is still in there and letting up on it can take this from a 1-time thing to a chronic ongoing issue. Also don't aim over 12, most of that chlorine loss is due to the sun and bringing it to 18 is not helping do anything but cause you to go through chlorine faster. Follow the process. You have to work with the schedule you have, we understand that, but trying to overshoot just wastes chlorine without speeding things up.

 

[Richard320]

Considering that an average pool can lose only 2 FC in 24 hours with sunlight on it for part of that, even 1 FC loss is rather generous. Which is a long way of saying that 1 FC loss is a hard rule.

Something is still using up the FC and it isn't sunlight. Check the ladder. Clean out the pump basket. Maybe even backwash. Just because you don't see inside, doesn't mean the filter isn't part of the same water.

As for swimming, generally up to SLAM is considered safe, but if they'll be drinking some, I don't know, Certainly if the water is clear you can let the FC drop some and let the kids in during the hot afternoons and take the FC up later. It's not as efficient, but it's also not as cruel as making them look at the clear pool on a hot day without being able to get in.

 

[Sivartb000]

1: Hard and fast rule, you still have something in the water
2: It is safe to swim up to SLAM level as long as you can see the bottom. If you have concerns get in and see if you can tell the FC is elevated, you will be pleasantly surprised.
3: See #2
4: Also see #2, though if the kids are getting more than a couple gulps then it's not unreasonable to want to drop it a bit

If you are concerned you can allow it to drop down in to the "Target Range", but you definitely want to keep the SLAM up afterwards. Something is still in there and letting up on it can take this from a 1-time thing to a chronic ongoing issue. Also don't aim over 12, most of that chlorine loss is due to the sun and bringing it to 18 is not helping do anything but cause you to go through chlorine faster. Follow the process. You have to work with the schedule you have, we understand that, but trying to overshoot just wastes chlorine without speeding things up.

Thank you for your advice. As for going over 12 is not going to speed things up, wouldn't I make progress slower and even losing progress if I were dropping below 12 everday? IE, if I get it up to 12 in the morning, and then cant check/add chlorine all day (100 degrees lately, and about 10 hours of direct sunlight before I get home) - it'd definitely be below 12 (probably guessing around 8) - wouldn't that cause losing some ground in the battle? Definitely not trying to argue, just trying to understand. Unfortunately during the week I have no choice and cannot tend to the pool between 7am and 6pm (sometimes later) - and I have direct sunlight on the pool by about 8am until about 8pm. I buy 2 gallons of 10% liquid chlorine for about $12, and so far I have used I think about 2 1/2 gallons. While I certainly don't want to waste money, its not breaking the bank and I'd be happy to spend a few extra bucks if it cleans it up faster. Unfortunately I don't have a good nearby source to buy bleach.

Either way, I think I'm super close to beating it - so I'm really hoping I meet my overnight test tomorrow morning.

Considering that an average pool can lose only 2 FC in 24 hours with sunlight on it for part of that, even 1 FC loss is rather generous. Which is a long way of saying that 1 FC loss is a hard rule.

Something is still using up the FC and it isn't sunlight. Check the ladder. Clean out the pump basket. Maybe even backwash. Just because you don't see inside, doesn't mean the filter isn't part of the same water.

As for swimming, generally up to SLAM is considered safe, but if they'll be drinking some, I don't know, Certainly if the water is clear you can let the FC drop some and let the kids in during the hot afternoons and take the FC up later. It's not as efficient, but it's also not as cruel as making them look at the clear pool on a hot day without being able to get in.

Thank you. I've been back washing every day and vacuuming every other day. The first 2 days were really dirty, the last few days the backwash was completely clear and there really wasn't much to vacuum, really only am doing it because SLAM says so lol. Which, now that I think about it, my test this morning may have been better if I vacuumed last night, I haven't vacuumed since Wednesday.

My ladder is removable, so no steps in the pool.

I think my plan is going to be to vacuum after work. go to bed with FC at 12 tonight and not add any chlorine in the morning. I have a lot of evaporation, so I need to add about 4 inches of water that will dilute the chlorine, and I'll leave the cover off Saturday morning and let the sun cook some FC off. By mid day Saturday, I should be quite a bit under SLAM level.

 

[Leebo]

Can you post a photo of your water?

 

[Sivartb000]

Can you post a photo of your water?

I will try as soon as I can, will be late this evening (kid has baseball practice tonight).

 

[Richard320]

Thank you for your advice. As for going over 12 is not going to speed things up, wouldn't I make progress slower and even losing progress if I were dropping below 12 everday? IE, if I get it up to 12 in the morning, and then cant check/add chlorine all day (100 degrees lately, and about 10 hours of direct sunlight before I get home) - it'd definitely be below 12 (probably guessing around 8) - wouldn't that cause losing some ground in the battle? Definitely not trying to argue, just trying to understand. Unfortunately during the week I have no choice and cannot tend to the pool between 7am and 6pm (sometimes later) - and I have direct sunlight on the pool by about 8am until about 8pm. I buy 2 gallons of 10% liquid chlorine for about $12, and so far I have used I think about 2 1/2 gallons. While I certainly don't want to waste money, its not breaking the bank and I'd be happy to spend a few extra bucks if it cleans it up faster. Unfortunately I don't have a good nearby source to buy bleach.

Either way, I think I'm super close to beating it - so I'm really hoping I meet my overnight test tomorrow morning.



Thank you. I've been back washing every day and vacuuming every other day. The first 2 days were really dirty, the last few days the backwash was completely clear and there really wasn't much to vacuum, really only am doing it because SLAM says so lol. Which, now that I think about it, my test this morning may have been better if I vacuumed last night, I haven't vacuumed since Wednesday.

My ladder is removable, so no steps in the pool.

I think my plan is going to be to vacuum after work. go to bed with FC at 12 tonight and not add any chlorine in the morning. I have a lot of evaporation, so I need to add about 4 inches of water that will dilute the chlorine, and I'll leave the cover off Saturday morning and let the sun cook some FC off. By mid day Saturday, I should be quite a bit under SLAM level.

Did you say cover?

Could there be something growing on the wet underside of it???

 

[Sivartb000]

Did you say cover?

Could there be something growing on the wet underside of it???

It is a solar cover, and is only a couple weeks old as I had to replace my prior one. I roll it up and take it out when I've been vacuuming. I handle it frequently and am looking at it the whole time I roll it up, so I definitely don't think theres anything growing on it (though i'm not necessarily inspecting it for algae, I feel that algae is on my radar enough I would definitely notice it).

It is a pretty small pool and the cover works very effectively (honestly too effectively when its 105 - 110+ for a few days in a row) - I'd guess my water is probably about 80* (I dont have a thermometer), could the warm water temp and/or having it covered be working against me in any way (other than if something is actually growing on the cover itself)?

 

[Richard320]

It is a solar cover, and is only a couple weeks old as I had to replace my prior one. I roll it up and take it out when I've been vacuuming. I handle it frequently and am looking at it the whole time I roll it up, so I definitely don't think theres anything growing on it (though i'm not necessarily inspecting it for algae, I feel that algae is on my radar enough I would definitely notice it).

It is a pretty small pool and the cover works very effectively (honestly too effectively when its 105 - 110+ for a few days in a row) - I'd guess my water is probably about 80* (I dont have a thermometer), could the warm water temp and/or having it covered be working against me in any way (other than if something is actually growing on the cover itself)?

By itself, no. But if you roll it up wet, stuff might grow while it's rolled up. There might even be some kind of film on it from when they molded it that's stealing your bleach. Try leaving the cover off for the OCLT. One day with a chilly pool beats another week SLAMming, doesn't it? I'd take the gamble.

 

[Sivartb000]

By itself, no. But if you roll it up wet, stuff might grow while it's rolled up. There might even be some kind of film on it from when they molded it that's stealing your bleach. Try leaving the cover off for the OCLT. One day with a chilly pool beats another week SLAMming, doesn't it? I'd take the gamble.

This cover hasn't been rolled up for more than maybe 3 hours this year - but, generally speaking, how long would something have to be rolled up to actually start growing anything? Unless I forget, the cover typically goes back on at night, so maybe 12hrs would be the longest it should be rolled up. Otherwise, yep - that makes sense and I agree worth the gamble, I will definitely try that. Thanks!

 

[Richard320]

This cover hasn't been rolled up for more than maybe 3 hours this year - but, generally speaking, how long would something have to be rolled up to actually start growing anything? Unless I forget, the cover typically goes back on at night, so maybe 12hrs would be the longest it should be rolled up. Otherwise, yep - that makes sense and I agree worth the gamble, I will definitely try that. Thanks!

I don't know.

But, see, it doesn't have to be growing to use up FC. If a kid (or an adult who is too drunk or lazy) pees in the pool, the chlorine takes a hit, but the urine doesn't grow. Anything that reacts with the bleach will consume the FC, so pretty much anything that can be oxidized - anything organic in the chemistry sense, not in the overpriced grocery sense -- can deplete FC. A mold release agent could be as simple as vegetable oil, and it could easily react with bleach.

 

[Sivartb000]

Thanks Richard - I understand what your are saying.

Heres a pic of pool prior to brushing the sides and vacuuming it (honestly I didn't see anything to even vacuum so I just did my best to cover the entire floor) not sure how I can get it any more clear than this! Will leave cover off and update oclt tomorrow morning.

 

[Sivartb000]

Fc dropped 1.5 again over night with cover off . But theres a good size collection of what appears to be dirt on the bottom, so maybe that ate some fc. I'm going to go ahead and let fc drop so we can use the pool this weekend. <0.5 cc and it's as clear as it's ever been. I will update if it appears to worsen again over the weekend/next week.

 

[mknauss]

You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.

 

[Sivartb000]

OCLT passed this morning with 0 FC drop!

Other question, I figured I'd ask here since this thread is still active. So I checked cya yesterday and it was low. My kit only measures to 30, and it was less than that, I'm "guessing" maybe around 20. A month or so ago it was 40, and just 2 weeks ago it was about 35. I decided to put a pound of cya in which would add a little less than 30ppm, getting it around 50. I used the sock method in front of the filter jet.

It surprisingly dissolved in just a couple hours. It sounds like I need to run my pump for 48hrs with no back washing for 48 hrs? Anything else I need to know? I couldnt find an article in the pool school about adding cya.

 

[mknauss]

I couldnt find an article in the pool school about adding cya.

Recommended Pool Chemicals

Which should I buy? TFP's recommended pool chemicals are cheap, easy, and won't unbalance your pool water.

www.troublefreepool.com

The article says to not backwash for a week after adding CYA. That is a bit extreme if the sock method is used.
You should not have to backwash very often. Be sure you let your filter pressure rise to 25% over the clean pressure before backwashing.

 

[Sivartb000]

Recommended Pool Chemicals

Which should I buy? TFP's recommended pool chemicals are cheap, easy, and won't unbalance your pool water.

www.troublefreepool.com

The article says to not backwash for a week after adding CYA. That is a bit extreme if the sock method is used.
You should not have to backwash very often. Be sure you let your filter pressure rise to 25% over the clean pressure before backwashing.

There it thanks. Thanks!