Annual SLAM (how do I always get here?)

aralph

Well-known member
Jun 22, 2015
83
St. Francisville
Had to SLAM this week after what I thought was an annoying dirt/pollen turned out to be algae after OCLT. I find myself here every spring. I live on the gulf coast with very mild Winters and wacky spring (30 one day, 80 the next). My question to fellow warm weather owners - when do you start maintaining chlorine levels & running your pump longer in order to avoid having to SLAM? Or do you just maintain all winter long? I'm guessing I need to start getting the pool in shape as early as Jan since this algae showed up in early Feb (we had warmest Feb on record this year). I'm getting too old for this! Never had this problem with my old saltwater pool. Thinking about converting this to saltwater when it comes time to drain & change the liner.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,888
Tucson, AZ
My pool is never "closed". By the time the "winter" months roll around (Dec-Feb), my SWG has already shutoff due to cold water cutoff (<56F water temp) and my pump runtimes go down to about 2 hours per day (skimming and cleaning only). I keep track of pH and FC and don't bother with any other measurements. I typically only need to add acid about once per month and, this past winter, I think I added two quarts of liquid chlorine in total the entire winter. We do get both cold and warm days in the winter months and some years we'll get a week or more where the overnight temps go below freezing, but it's simply not worth it to winterize a pool where I live. I never need to SLAM when the weather warms up.

So, if you simply maintain your pool chemicals a little better over the winter, I'd bet you would be in the same situation. Algae problems typically occur when the water warms up enough to allow for growth and the chlorine is too low to inhibit it. So, even though the water may look clean, algae is always there and ready to bloom once the water stays above 60F.
 

Patrick_B

TFP Expert
LifeTime Supporter
Jun 7, 2011
14,999
Midland TX
It's a matter of going into winter in very good shape with routine testing of your pool, especially where its warm. Winter will be less demanding on Chlorine.

Giving it to you with no fluff or spin, you are simply not maintaining good Free Chlorine levels like you should. Are you using a good test kit? You won't have to test anywhere near as frequently in winter or summer once you know your pool extremely well. When you do, you will get a feel for what it needs. In time, with diligent attention, you can accurately predict about what the pool will need even prior to testng it. When you do, and keep things like they should be, this yearly problem will go away.
 

aralph

Well-known member
Jun 22, 2015
83
St. Francisville
Absolutely have the right test kits and I test diligently throughout summer and fall. Spring warm spells seem to catch me off guard though. One warm week and I'm screwed. Like I said we have big temp swings here in spring. I think I need to watch my water temps much more closely and start hitting with chlorine when it reads 60.

- - - Updated - - -

What SWG do you have? I'll be in the market soon as I don't have much liner life left - maybe 2 more yrs at best.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,888
Tucson, AZ
Yes. It would probably help if you just developed the attitude that your pool is a "year 'round" pool and simply perform standard pool maintenance all year long. What you will find is that during the winter months your pool will a lot less chlorine and testing can be performed on a less frequent basis. You can also just run the pump for a few hours per day or every other day to maintain cleanliness. As Patrick said, once you get a feel for it, you can simply dose your pool as needed and then confirm with a few simple tests that your water is still balanced. Leaving a pool open and unattended for prolonged periods of time is usually what causes problems.

For example, two winter's ago I was very busy and did not really test my pool frequently enough. Because the pH was likely running very high most of the time and I was not adding acid, I got horrible calcium scale all over my pool tiles. It was so bad that I needed to bring in a professional to soda blast the calcium off which cost me $300. Had I simply tested my pH once a week and added the acid as-needed (literally 5 minutes worth of my time), I could have saved myself the cost.

It's just a fact of life for those that live in the southern climates with pools - they need to be maintained consistently throughout the year or else problems will crop up.

- - - Updated - - -

I have all Pentair equipment with automation so it makes sense to keep all the equipment in the same family. There are many high quality, stand-alone SWGs on the market. Discount Salt Pools has the best information regarding SWG comparisons -

Compare and Review Saltwater Chlorine Generator Prices and Features
 

aralph

Well-known member
Jun 22, 2015
83
St. Francisville
Thanks for the responses. I may just go ahead and buy an SWG. I have to add a gallon of bleach/day in summer and it gets old.

SLAM question: started it nearly a week ago. Still failing the OCLT. CYA is between 50 and 60 (depending on how hard I "look" for the black dot). Been trying to keep FC over 25ppm. Sweeping every few hours. Any ideas? Should I bump the FC up higher? Or drain/fill to get CYA down? I have no CC in the pool.
 
Last edited:

Jezza

LifeTime Supporter
TFP Guide
Jan 18, 2015
969
Bunbury, WA, Australia
How often are you testing and re-dosing to SLAM level. Also keeping a record of your FC loss between tests often helps.

You seem to have the right SLAM level if your CYA is 60. Has your water shown any improvement in clarity?

Taking photos looking down the steps often helps when you feel as though your not going anywhere
 

Holydoc

Well-known member
Jul 17, 2016
268
Navarre/FL
I test my pool weekly during the winter to ensure that FC is maintained. Typically I am lazy and bring the pool up to SLAM level which allows me to go for a couple weeks without adding anything during the winter. When it hits Spring (like today) I keep my water around its maximum FC level (typically around FC = 9 for CYA = 60) and check it every three days usually having to add a gallon of 10% when the FC drops to FC = 6. Of course once it hits swimming temperatures, I am adding chlorine daily.

I also check the skimmer basket every time I check the water. Usually it is full of leaves that I dump out. I have a two speed pump that I leave on 24/7 on low speed (~$10/month cost). And about twice a month during winter, I run my Dolphin Nautilus Plus robot to keep the floor clean and ready for Summer.

Hope this helps some.
 

aralph

Well-known member
Jun 22, 2015
83
St. Francisville
Have been testing/re-dosing every few hrs. Haven't allowed it to drop below 20ppm. It's super clear, so feels like I'm close. But OCL has been between 3-5ppm. Algae on steps not as prominent as it was but I've been at this "close" stage for a couple of days now. I screwed myself by adding 3-4lb of CYA initially as it was too low to measure. The additional CYA shot it up over 50 even though the directions said I needed much more to reach that level,
 

Jezza

LifeTime Supporter
TFP Guide
Jan 18, 2015
969
Bunbury, WA, Australia
Yep been there done that with the CYA- doh!!

Have you done the normal checks of the algae hiding places- behind light niches, in and around skimmer boxes, removable ladders etc?
 

domct203

Bronze Supporter
LifeTime Supporter
TFP Guide
Jun 3, 2015
3,959
CT
Have been testing/re-dosing every few hrs. Haven't allowed it to drop below 20ppm. It's super clear, so feels like I'm close. But OCL has been between 3-5ppm. Algae on steps not as prominent as it was but I've been at this "close" stage for a couple of days now. I screwed myself by adding 3-4lb of CYA initially as it was too low to measure. The additional CYA shot it up over 50 even though the directions said I needed much more to reach that level,
If you are still seeing any algae at all, don't even bother with the OCLT yet, you'll just drive yourself nuts LOL.
 

aralph

Well-known member
Jun 22, 2015
83
St. Francisville
Did an extra good clean last night in all the less than obvious places. I hadn't cleaned the actual sides (non sloped) so did that as well. Don't see algae there.
 

aralph

Well-known member
Jun 22, 2015
83
St. Francisville
Check behind the light, inside skimmer/autofill, under/around ladders, on/in anything that is floating around, etc.
When you say behind the light, do you mean remove the actual light and housing and clean behind it? Or are you just recommending trying to scrub in between light and wall?
 

triptyx

TFP Guide
Apr 12, 2016
1,495
Tucson, AZ
Remove the actual light (with its housing) and scrub the alcove behind it. It's a favorite place for algae to hide when you're SLAMming.

Edit - To be clear, with a vinyl pool, you just want to remove the light itself - don't try to remove the entire housing/niche! If you're confused, let us know and we can give you more detailed instructions.
 

triptyx

TFP Guide
Apr 12, 2016
1,495
Tucson, AZ
Pretty likely. Some folks leave the light out of the niche while SLAMming to ensure that area receives fresh, chlorinated water throughout the SLAM.
 

aralph

Well-known member
Jun 22, 2015
83
St. Francisville
I did the same. I think I found the hiding spot. A fountain PVC attachment that connects to my jet for aeration.

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Patrick_B

TFP Expert
LifeTime Supporter
Jun 7, 2011
14,999
Midland TX
I am glad you found that, but there is more to this with it being the situation every year, and I would lie by omission not to say so. All good though, you have the tools and knowledge to cure it. Be vigilant with FC balance from here out, and you won't have to worry with it next year. :goodjob:
 
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