SLAM’ing too often!

[poolflyer]

I took over my pool when I installed a SWG in February. Since then, it’s been mostly good. I typically keep my FC @ 10 with a CYA of 70, so on the high side to account for any Florida downpours during the summer. I test twice a week, aim to brush every 7 days or sooner. My SWG currently runs at 80% for 7 hours a day- so adding about 3.4 FC per day for my pool- seems to be the sweet spot for the summer to keep it at 10 FC. It has a screen cage and gets very little debris in the pool, but a lot of sunlight this time of year. This last 8 weeks we’ve used the pool maybe twice, just two people. I have a Hayward Pool Vac XL that runs on the VSP (12 hours a day, 3 hours at high speed), but doesn’t climb the walls to clean them.

My problem: I had a few episodes (4 since February) where FC would be close to zero and I’d have to SLAM. I found that was typically after ~10 days of not sweeping the pool, only correlation I could gather.

I was just out of town and the pool went unswept for about 10 days. Came back to a FC of 0.5. Crud! Again!!! It was perfect when I left! So currently undergoing SLAM right now, day 3. No green, no smell, not cloudy- just thirsty of chlorine (like all the other times).

I was cleaning my CC150 cartridge filter about once a month. I read on here that seemed to be overkill. Last time I cleaned it was about 2.5 months ago. Today I decided I’d clean it and it was a little slimy and quite dirty. I was surprised by this. Should I stick to once a month?

Sorry for the scatterbrained post. I’ve got the SLAM process figured out- I’m just trying to figure out why I seem to be repeating this process- what’s killing me FC and making me do this every few months? Everything seems to be going great for a while and then suddenly one day it isn’t!

The only thing I can seem to correlate is if I wait more than ~10 days to brush it. Could this be my main culprit? Anything else I could be missing? Just getting frustrated with having to do this every ~7 weeks!

Thanks for your thoughts on what’s causing this! Stats below if curious.

FC tonight: 30 (SLAM recommends 28)
CC 0.5
PH 7.2
TA 70
CYA 70
CH 350
Salt 3200
Temp ~84°F
Solar panels off, pump 3450 RPM 24/7 right now (only for SLAM)

 

[PoolStored]

Clean your filter when pressure rises 25% over clean pressure.

Follow the basic pool care schedule:

Basic Pool Care Schedule

This basic pool care schedule can guide you in creating your own pool care routine. Regular pool maintenance will keep your water sparkling!

www.troublefreepool.com

Make sure to follow the FC/CYA chlorination schedule with your SWCG. Link-->FC/CYA Levels

Turn up your SWCG if you go away.

Follow the SLAM process to rid your pool of algae...Link-->SLAM Process

 

[pjt]

FC would be close to zero and I’d have to SLAM

What was the cause of the FC loss?

Came back to a FC of 0.5

Are you sure the SWCG was generating? You might have had contaminants in your water consuming your FC.

Today I decided I’d clean it and it was a little slimy and quite dirty. I was surprised by this. Should I stick to once a month?

You probably had an algae bloom, which would explain the loss of FC and slimy filter cartridge. This is a chemistry issue, not a filtering issue.

FC tonight: 30

Is this a typo or really 30?

How are you testing?

pump 3450 RPM 24/7 right now

Why? You have a VSP. Run your pump as slow as possible while still satisfying your requirements (SWCG flow switch, skimmers functioning, etc.).

 

[Bperry]

I took over my pool when I installed a SWG in February. Since then, it’s been mostly good. I typically keep my FC @ 10 with a CYA of 70, so on the high side to account for any Florida downpours during the summer. I test twice a week, aim to brush every 7 days or sooner. My SWG currently runs at 80% for 7 hours a day- so adding about 3.4 FC per day for my pool- seems to be the sweet spot for the summer to keep it at 10 FC. It has a screen cage and gets very little debris in the pool, but a lot of sunlight this time of year. This last 8 weeks we’ve used the pool maybe twice, just two people. I have a Hayward Pool Vac XL that runs on the VSP (12 hours a day, 3 hours at high speed), but doesn’t climb the walls to clean them.

My problem: I had a few episodes (4 since February) where FC would be close to zero and I’d have to SLAM. I found that was typically after ~10 days of not sweeping the pool, only correlation I could gather.

I was just out of town and the pool went unswept for about 10 days. Came back to a FC of 0.5. Crud! Again!!! It was perfect when I left! So currently undergoing SLAM right now, day 3. No green, no smell, not cloudy- just thirsty of chlorine (like all the other times).

I was cleaning my CC150 cartridge filter about once a month. I read on here that seemed to be overkill. Last time I cleaned it was about 2.5 months ago. Today I decided I’d clean it and it was a little slimy and quite dirty. I was surprised by this. Should I stick to once a month?

Sorry for the scatterbrained post. I’ve got the SLAM process figured out- I’m just trying to figure out why I seem to be repeating this process- what’s killing me FC and making me do this every few months? Everything seems to be going great for a while and then suddenly one day it isn’t!

The only thing I can seem to correlate is if I wait more than ~10 days to brush it. Could this be my main culprit? Anything else I could be missing? Just getting frustrated with having to do this every ~7 weeks!

Thanks for your thoughts on what’s causing this! Stats below if curious.

FC tonight: 30
CC 0.5
PH 7.2
TA 70
CYA 70
CH 350
Salt 3200
Temp ~84°F
Solar panels off, pump 3450 RPM 24/7 right now.

That’s not a brushing issue. You need to test more often and replenish the FC manually if needed.

 

[Jimrahbe]

PF,

If you have to SLAM more than once, in a location where the pool is never closed, then you are simply not doing it correctly..

Once you SLAM, you should never get algae again, unless you don't maintain the proper FC to CYA ratio..

In most cases, this is caused by trying to run your FC as low as possible. When in reality, it is better to run your FC at the high end of your target range.

Thanks,

Jim R.

 

[poolflyer]

What was the cause of the FC loss?


Are you sure the SWCG was generating? You might have had contaminants in your water consuming your FC.


You probably had an algae bloom, which would explain the loss of FC and slimy filter cartridge. This is a chemistry issue, not a filtering issue.


Is this a typo or really 30?

How are you testing?


Why? You have a VSP. Run your pump as slow as possible while still satisfying your requirements (SWCG flow switch, skimmers functioning, etc.).

That's my point- I can't pinpoint any cause of the FC loss- that's what I'm asking to help me find that!
Yes, the SWG was generating, unless there is something wrong with it that isn't showing apparent to me. Appears to be functioning normally. It's on a smart switch and I can see and control what hours per day it runs.

Yes, FC was 30 last night. SLAM recommends 28 for my CYA of 70. Went slightly over. Testing using Taylor 2006C.

You must've not have seen earlier in my post- I said that it runs on a low speed schedule most of the daylight. Just running it 24/7 right now for the SLAM- as per the SLAM recommendations.

 

[poolflyer]

PF,

If you have to SLAM more than once, in a location where the pool is never closed, then you are simply not doing it correctly..

Once you SLAM, you should never get algae again, unless you don't maintain the proper FC to CYA ratio..

In most cases, this is caused by trying to run your FC as low as possible. When in reality, it is better to run your FC at the high end of your target range.

Thanks,

Jim R.

I totally agree Jim. I have been running my CYA @ 70 and my FC at 10- so I am on the high side. That's why I don't understand why I'm having this issue.

When myself or my wife is at home testing and brushing twice per week, it is absolutely perfect. Testing has been more affirming- no changes required to SWG schedule or settings- hanging right at 10 FC (+/-1PPM). For the last few summer months my SWG is on a % and time schedule that seems to be a perfect match with FC consumption (~3.4 FC per day), we haven't touched the settings in months. It's be purring like a kitten- absolutely perfect and trouble free!

...But the moment we both leave town and don't brush after ~9 days is when the 'it' hits the fan! The only thing I can think of is every time I leave out of town for more than a few days, I should start increasing the SWG % to give it a surplus over consumption.

 

[proavia]

But the moment we both leave town and don't brush after ~9 days is when the sh*t hits the fan! The only thing I can think of is every time I leave out of town for more than a few days, I should start increasing the SWG % to give it a surplus over consumption.

Try turning up the percentage 5%-10% when you leave. You can always practice that when you're home to see how it works - just treat the pool like you aren't there. You may return and find the FC a little high, but still below SLAM level.

 

[SecoSteve]

Could it be that the water is not moving enough when you're away? Why not run 24/7 at higher speeds when you leave the pool for days?

 

[Jimrahbe]

.But the moment we both leave town and don't brush after ~9 days is when the 'it' hits the fan!

PF,

Here is my 'guess'...

On the surface I would not think that sweeping should make any real difference... But.. Are you just sweeping the whole pool or are you sweeping places that are attracting algae? In my mind, you either have algae or you don't. For those that have low levels of algae, adding enough 'shock' can keep algae at bay.. That is why dumping in bags of pool store shock appears to work for most people.. I suspect that sweeping tends to break up any algae that is there, and allows the FC to kill most of it, just not all of it.. So, when you quit sweeping, the algae has time to multiply, until it is visible..

What I would do if I were in your shoes, the next time I did a SLAM, I'd run at a higher FC and for two days longer, just to make sure. I'd also look for places that algae can hide and clean them.. Like inside a light niche, or inside or under ladders, etc.

I have three saltwater pools that are all well over 10 years old.. I have never had algae in any of them... So I have no actual SLAM experience.. I run all three pools 24/7, at a low RPM.. All three pools have Robot cleaners.. In that time I have never swept the pools.. Maybe that will come back and bite me, I don't know, but my point is that I don't think that not sweeping is the issue.

Thanks,

Jim R.

 

[Pauls234]

Others have mentioned it, but don't want it to get lost in the shuffle- test your FC more frequently so we have more data points.

My next comment was going to be pretty much exactly what Jim R. said above, that you may have a low level algae problem as it survives in some little corner, inside ladder, light niche, on the foam wier door, etc. the usual suspects but the brushing helps keep it (visibly) at bay. That would explain the correlation you are observing, but the cure is not brushing more frequently it is fully eradicating the algae, wherever it might be hiding.

But it's still just conjecture. Test FC every day if you can and let's see what that shows.

 

[Bperry]

I think I would stop brushing while you are home and make sure to log all test results for a few weeks and see what happens. You should not get algae due to lack of brushing.

 

[JJ_Tex]

I'll take a guess.

Your SWCG is working normally at low speeds, but you have a small filter. As the days go by and your filter does it thing, suddenly the rpms at low are not enough to keep your SWCG happy so it doesn't generate chlorine like you think it is and suddenly you get algae. Then you SLAM, clean the filter, etc. and start the cycle over.

If that's a plausible guess, test more often and check your flow sensor often and bump up your low speed rpms if needed.