SLAM, SLAM again, SLAM some more--Why do I have to do it again and again

[frog760]

Hello all,

My SW Florida pool is 3 1/2 years old. The first 3 years have been trouble free. We brush, vac, and clean the filter weekly. Usually need to add about a quart of acid a week to week and a half to keep the PH under control. That's about it...until 6 months ago.

We started having trouble maintaining Chlorine. It would drop to zero overnight...we try to keep it around 5-6. We tried lots of potions and concoctions from the local pool places--all to no avail. New cartridge filter, followed by another a week later. Pool store had no clue as all the chems were normal. Then I found this website and learned about the SLAM. Leslie's manager never even heard of SLAM.

Our first SLAM was around Thanksgiving last year and it took about 5 days. Passed the OCLT and all was well...so we thought. Two months later, it happened again. This time we got on the SLAM right away and it only took 3 days this time. Now, nearly two months later, it started again. Chlorine of 15.6, next day 9.0, day after 1...all while the SWG is at 50% and the pump running 10-hours a day. Normally our SWG is at 5-10% depending on the time of year. Water got cloudy when the Chlorine dropped to 1, otherwise it's been clear. I grabbed a sample of water from the return and the SWG is making Chlorine.

There are no pets or kids using the pool. It's enclosed in a screened cage. We only use the pool about 1-2 hours a day and it stays under a solar blanket when not used. Most of the time it's only one person using the pool. Hardly any rain and the temps been in the upper 80s lately.

Last full chemistry: 4/13/22, FC 9.0, PH 7.4, TA 90, CH 360, CYA 60. In case the specs are not on the side: 11x26, 3'-5', Hayward systems...small pools, fast changes.

So the million dollar question...WHY? Why do I have to SLAM every other month when I didn't for 3-years? Third SLAM begins in the AM, just grabbed 5 gallons of liquid gold from PaP.

 

[kimkats]

Hi and welcome to TFP. From the sounds of it I am guessing you have your own test kit. Please correct me if I am wrong.

I have a couple of ideas but they all depend on how your testing your water.

 

[frog760]

Have the big Taylor kit...Leslie's is a few miles away for confirmation (prefer their computer vs PaP's visual). Chems are 6-months old and unexpired.

 

[Bperry]

Have the big Taylor kit...Leslie's is a few miles away for confirmation (prefer their computer vs PaP's visual). Chems are 6-months old and unexpired.

What level do you normally keep the chlorine level at and how often do you check it? If you keep getting algae it sounds like it’s getting below the minimum.

 

[kimkats]

tried lots of potions and concoctions

Can you name any of of them?

It looks like you know about the FC/CYA chart as seen here:

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

Now I did see where you said the FC got down to 1. How often does that happen? and for how long?

Can you please fill in your signature so we have all of your pool details at a glance. The side bar does not always show up.

 

[YippeeSkippy]

Some pool store poisons oops, I mean POTIONS are NOT recommended here and can cause your chlorine to get chewed up and not available to kill the cooties and algae. Aluminum is an example of a *bad* chemical to add.

Your SWG must be incredibly oversized if you're only running it at 5-10%.

Can you provide us these values from your own test kit:
FC
CC
pH
TA
CH
CYA
Salt level

How often do you normally test?

Is your filter actually dirty and the dial up 20% over baseline each week causing you to have to clean the filters?? Or perhaps too small for your pool? What size are the filters?

We need more info!

Maddie

 

[frog760]

Pool is 11x26, 3' to 5' (as stated in OP) quartz aggragate interior finish (original contract's wording). 1.5hp Hayward variable speed pump, running about 10 hours everyday. Hayward 1500 cartridge filter...cleaned weekly and most times is dirty and rinses to pure white. 110K BTU heat pump. Aqua Rite salt chlorinator with T-15 cell. Latest full chems are in OP...salt is 3000. Water temp is 85-89. No pool store potions have been used since mid Nov--when I found this site and was enlightened. We brush and vac weekly...then rinse filter. Full chems before cleaning and add acid as needed...haven't for two weeks. During the week, we'll spot check the chlorine a couple of times and adjust the SWG as needed. Water has never been green...only cloudy on the occasion. Started the SLAM at 10am today...added 2 gallons of liquid gold and turned off SWG.

Noon, FC 24.4, added 1/2 gallon
2pm, FC 28.6, added 1 qt
4pm, FC 26.6, added 3 qts
6pm, FC 30.4 added 1 qt
8pm, FC 34...covered for the night, pump set to run all night

In the AM, will test FC, brush and vac, and rinse filter.

 

[Newdude]

Hey frog !!! Which SWG do you have ? 3.5 years with long FL seasons is a good run for a unit that was properly sized. We are among the few who promote oversized units. But usually they either work or they don't and it appears it is still making chloine so thats a good sign for now and we mihht just have some tweaking to runtime and CYA levels. But its also possible that the unit or the controller stopped/broke in one (of 2) of the polarity settings, effectively only working half the time. Just enough to go a short while between SLAMs and fool most people.

But. If you want some proof to NEVER listen to the pool store, the filter filters particles (dirt/pollen). If it fails the pool will be cloudy but keep the FC with nothing chemically or organically (living algae) wrong. The 'professionals' suckered you into a $1500(?) piece of equipment because they have no clue about chemistry or equipment. I hope you saved the 3 year old one. It will fetch TOP dollar with all the shortages. Maybe even MSRP.

Mystery potions are exactly that and even the pool store people can't state with fact, what they do. 'Well..... you..... um.... see...... this here is 7 in1 extra blue. You want blue water dont ya ???' Spin the bottle/bag around and copper is listed. The same copper that they have 27 mystery potions to remove. And a 'free test' to prove you need the potions. Go to the pool store when you want bleach, some small parts, a new float, etc. Let any and all advice go in one ear and out the other. Pass on the free test, its designed to keep the store open and its results mean nothing.

 

[Bperry]

Pool is 11x26, 3' to 5' (as stated in OP) quartz aggragate interior finish (original contract's wording). 1.5hp Hayward variable speed pump, running about 10 hours everyday. Hayward 1500 cartridge filter...cleaned weekly and most times is dirty and rinses to pure white. 110K BTU heat pump. Aqua Rite salt chlorinator with T-15 cell. Latest full chems are in OP...salt is 3000. Water temp is 85-89. No pool store potions have been used since mid Nov--when I found this site and was enlightened. We brush and vac weekly...then rinse filter. Full chems before cleaning and add acid as needed...haven't for two weeks. During the week, we'll spot check the chlorine a couple of times and adjust the SWG as needed. Water has never been green...only cloudy on the occasion. Started the SLAM at 10am today...added 2 gallons of liquid gold and turned off SWG.

Noon, FC 24.4, added 1/2 gallon
2pm, FC 28.6, added 1 qt
4pm, FC 26.6, added 3 qts
6pm, FC 30.4 added 1 qt
8pm, FC 34...covered for the night, pump set to run all night

In the AM, will test FC, brush and vac, and rinse filter.
View attachment 401691

What is the normal FC level you stay above during the year? That will likely help determine what’s going on.

 

[Flying Tivo]

the pump running 10-hours a day. Normally our SWG is at 5-10%

If your pool is around 8,600gallons
10 hrs@10% is only producing 1ppm of FC, this is why you get algae.
You need at least 42% for 10 hrs to produce 4ppm which is what a regular pool consumes daily.
Or 4 hrs running at 100%. Since you have a variable speed pump the best is to run it as low as the SWG will allow for the daylight hours.
When you ran it at 50% you already had the algae bloom so the SWG could not keep up.
This time around after the SLAM keep your T-15 at 40% for the 10hrs. Try to keep your FC at 8 for a CYA 70.

 

[PoolBrews]

I'm in Central Florida, and like frog760, I have experienced the same issues. My last two pools were in MI and GA, and I had to SLAM maybe once a year there - usually when opening. Here in Florida, I initially had to SLAM about once every 2-3 months. Now that I've been monitoring it for 3 years, it's down to about every 3-4 months.

I can't let my pool get down to the recommended chlorine/CYA levels or I am guaranteed to wake up to a cloudy pool. The chart says that at a CYA of 80, I should have a min FC of 4 with a recommended FC of 6. I keep my CYA at 80, and if FC drops below 11 or 12, I know I'm in trouble. I've never had this pool at an FC of below 10 where the water has remained clear. I typically only run the cell around 10%-20%, but it's a 40K cell for a 7K pool.

I have found that the regular heavy rains we have, and the pollen dumps can dramatically impact CYA and chlorine levels. Initially I tested CYA every couple of weeks, just like in MI and GA. I would find the CYA depleted down to 40 or 50, and the water going cloudy. Now I test after any rainstorm of significance, or when I see pollen on my outdoor furniture. Keeping CYA where it needs to be has helped tremendously.

I have just accepted the fact that I need to keep my FC high - I don't really understand why, but the results are obvious.

My recommendation is to test CYA more frequently and ensure it remains at the level required. When you see chlorine dropping, make sure you bump up your cell output.

 

[march2012]

Pool is 11x26, 3' to 5' (as stated in OP) quartz aggragate interior finish (original contract's wording). 1.5hp Hayward variable speed pump, running about 10 hours everyday. Hayward 1500 cartridge filter...cleaned weekly and most times is dirty and rinses to pure white. 110K BTU heat pump. Aqua Rite salt chlorinator with T-15 cell. Latest full chems are in OP...salt is 3000. Water temp is 85-89. No pool store potions have been used since mid Nov--when I found this site and was enlightened. We brush and vac weekly...then rinse filter. Full chems before cleaning and add acid as needed...haven't for two weeks. During the week, we'll spot check the chlorine a couple of times and adjust the SWG as needed. Water has never been green...only cloudy on the occasion. Started the SLAM at 10am today...added 2 gallons of liquid gold and turned off SWG.

Noon, FC 24.4, added 1/2 gallon
2pm, FC 28.6, added 1 qt
4pm, FC 26.6, added 3 qts
6pm, FC 30.4 added 1 qt
8pm, FC 34...covered for the night, pump set to run all night

In the AM, will test FC, brush and vac, and rinse filter.

You also shouldnt need to clean the cartridge weekly. Just monitor the pressure and clean when the pressure gets too high (this is dependent on your system). Mine is oversized so I clean the filter about once per year. With your screened in pool i would think you would only rarely need to clean it.

 

[cowboycasey]

Your in Florida and while a great place to live, pools have some problems there..

1. small filters that need cleaned often..
2. lots of rain that dilutes your FC and CYA.. Test FC 2 times a week and CYA weekly
3. Cages, You get lots of stuff collected on them for a time and then it rains, all that gunk gets dropped in your pool all at once instead of over weeks with small amounts.. When that happens your FC takes a hit and your pools go cloudy...

Recommend you keep CYA at 80 and FC at 8 to 9 at all times.. any kind of heavy rain go out and check your levels ASAP and adjust.. Better yet when you know it is going to dump rain turn the pump on and set the SWG on 100% till the rain stops and test after.. And keep 25 pounds of CYA on hand as your pool goes through it like crazzzzzy...

 

[frog760]

If your pool is around 8,600gallons
10 hrs@10% is only producing 1ppm of FC, this is why you get algae.
You need at least 42% for 10 hrs to produce 4ppm which is what a regular pool consumes daily.
Or 4 hrs running at 100%. Since you have a variable speed pump the best is to run it as low as the SWG will allow for the daylight hours.
When you ran it at 50% you already had the algae bloom so the SWG could not keep up.
This time around after the SLAM keep your T-15 at 40% for the 10hrs. Try to keep your FC at 8 for a CYA 70.

That makes perfect sense. Thanx...