Algae bloom and not sure why.

[TigerFanatic1]

Had an algae bloom and can't determine why.
Short story (addition recent history under long story, including SWG failure):
Had an algae bloom and can't determine why.
Circulate pool ~12 hours per day, SWG set at 80% power.
FC - 6
pH - 7.3
TA - 70
CH - 175
CYA - 70
Salt - 3600 per drops, 3470 per SWG
Phosphates - waiting on kit to arrive, never tested.

Long story: (Note I work away from home for days or weeks at a time, so you may see the trend )
Opened pool around mid-April utilizing SLAM and liquid sodium hypochlorite, without SWG installed. Once the pool had minimal cloudiness, I added salt and installed the SWG. Pool continued to improve over a period of time and we set the SWG up to maintain the FC level running 18 hours per day and SWG at 60%, FC-7. Being that I had to leave for work around the time we got everything looking good, I decided to leave the 18-hour circulation and not risk any undesirable events. 3 days later I was told the pool the pool had a light green tint to it and FC was a 2. Advised family on SLAM dosage needed and started the process again, including running pump 24 hours per day and increasing SWG to max power. Throughout the next week, we had to keep adding liquid sodium hypochlorite, because the SWC would lose about 2 PPM of FC per day. Once day my family noted that the SWG was generating and had a "Cell Connection" message, so they powered down for a few minutes and placed back online. The need for liquid hypochlorite continued until I arrived home. Once home I completed the overnight test, 0 loss of FC, so I contacted Circupool about issues. Circupool sent a part to replace inside the unit and the FC began to generate enough FC. I began to dial in SWG and timer ending up running the unit 12 hours per day at 80% power and would only lose about 0.5 FC on days that hit 95°.

I depart for work again with the FC at 9, family is taking the daily FC test to ensure the yellow color indicates that the FC is above 5. On day 3 away from home they conduct a drop test with FC still at 9. Miss 2 days of the daily tests, get approximately 1.1" of rain between days 4 and 5. On day 6 the pool is a dark green on the deep end, with drop test indicating FC of 6. With an FC of 6, I have no idea how or why algae formed, so I'm missing something. Rain rarely affect any of my numbers, especially just an inch. I'm currently waiting on Phosphates test kit to arrive. Any advice will be much appreciated, as the pool is getting the best of us. We are currently shocking the pool set the SWG to max power running 24-hours per day.

 

[mknauss]

At any time have you passed all three criteria for a successful SLAM at the same time?

 

[Newdude]

Any advice will be much appreciated,

If you properly SLAMed and finished it to completion, your long story would have included daily brushing, vacuuming, scrubbing every inch, filter cleans when psi increased 25%, and passing all 3 exit criteria.

Phosphates isn't your problem. Effort is your problem. And it doesn't make you 'bad', it means life got in the way. Believe ME we all get that. But if you want to to end it, you need to put the effort in. Train as many helpers as you need if you are skipping town for a spell. They need to put the effort in while you're away as well.

 

[TigerFanatic1]

At any time have you passed all three criteria for a successful SLAM at the same time?

Yes, both the opening and the first outbreak all three criteria were met.

 

[mknauss]

Once the pool had minimal cloudiness

You ended the SLAM there it sounded like.

If you have crystal clear water, no fc loss overnight, and no cc, that ends a SLAM.

 

[Newdude]

Yes, both the opening and the first outbreak all three criteria were met.

OK. That's a HUGE missing part of the 'long story'.

Repeated SLAMs (when properly completed) are usually due to algae hiding in plain sight that was missed. Light niches, skimmers, autofills, ladder rails, etc. It starts reintroducing it immediately and the full bloom returns a shot while later.

 

[TigerFanatic1]

OK. That's a HUGE missing part of the 'long story'.

Repeated SLAMs (when properly completed) are usually due to algae hiding in plain sight that was missed. Light niches, skimmers, autofills, ladder rails, etc. It starts reintroducing it immediately and the full bloom returns a shot while later.

Agreed, it isn't very visible, as all I stated was starting the SLAM. For the long story, I mostly wanted to highlight that I properly SLAM'd to open, set up SWG, had an outbreak which I assumed was due to SWG malfunction and low FC confirmed that (in my mind). Then another SLAM was completed , SWG repaired, water balanced (mostly allowing FC to decrease and adding CYA), then boom another outbreak.

Below is my best shot at a more focused timeline of what happened after returning home after outbreak and family completing their part of damage control. I've looked at way too many numbers today, so a couple of things may be out of place, typo, etc.

1. 5/25 7:30 am - arrived home, pool clear with algae dropout build up in seams. FC - 10.5, CC - 0, pH - 7.7, TA - 80, CH 150, CYA - 60, SALT - 3800. Vacuumed build up, swept pool, backwashed, added small amount of DE, added unknown volume of water (I'm slow at vacuuming), add 2 gallons of chlorine . At this point, I'm likely days outside of SLAM due to FC being below SLAM required levels.
2. 5/25 9:00 pm FC 12.5 (drop test), shutdown SWG (still not functioning properly, but haven't confirmed), leave pump circulating 24-hours per day
3. 5/26 8:00 am FC 12.5 (drop test), restart SWG, water is clear with very few dropout build up spots, vacuum to filter, added 2 gallons of chlorine, and approximately 2 lbs. of stabilizer.
4. 5/27 8:00 am FC 20.5 (drop test) water still clear and no cloudiness noted on following days, no dropout noted on bottom of pool or steps, at this point I believe the SLAM is over and am convinced the SWG is functioning correctly. Past history I need a little more than a gallon of 10% chlorine per day in the extreme heat, so I quit drop test and just ensure it's greater than 5 on the daily quick test kit for a couple of days to test the SWG output over a few days.
5. 5/30 2:00 pm FC 16.5 (drop test), water clear. I'm thinking the SWG is not functioning correctly because it's losing over 1 PPM per day running at max output around the clock, and is more than double the size needed for pool...but, I'm also second guessing my SLAM results because SWG is basically new.
6. 5/31 9:30 pm FC 15 (drop test), shutdown SWG, but leave pump circulating 24-hours per day.
7. 6/1 7:00 am FC 15 (drop test) CYA 70, I'm convinced SWG is not functioning correctly and call Circupool, they decide to send me the part. SWG placed back online because it is generating some volume of FC.
8. 6/3 1:00 pm FC 13 (drop test)
9. 6/4 receive and install part, kids want to swim so I backwash filter which was about 25 psi (was 22after adding DE on 5/25), sweep noted pool still clear, pH 7.2, let kids start to swim while adding unknown volume of water to replace.
   1. 9:00 pm post swim FC - 8.5, CC - 0.5, pH - 7.2, TA - 70, CH 175, CYA - 60, SALT - 3600. Added approximately 2 lbs. of stabilizer, set SWG to 80% power and pump on 7:00 am - 7:00 pm run time.
10. 6/5 8:00 pm FC - 9.5
11. 6/6 2:30pm FC 9 (drop test) pH - 7.3, CYA - 70
12. 6/9 12:00 pm FC 5+ (daily test kit, I forget what it's called but one with pH on opposite side)
13. 6/11 1:00 pm FC 9
14. 6/11 late evening and throughout the 12th 1.1" of rain
15. 6/13 2:00 pm FC 6 (drop test) and algae bloom.

Edited to add step 14 and include the rain.

 

[TigerFanatic1]

You ended the SLAM there it sounded like.

If you have crystal clear water, no fc loss overnight, and no cc, that ends a SLAM.

Technically yes, because I shutdown circulation for about 6 hours to install cell and flow switch, allowing time for glue to cure. I did however, add additional chlorine above SLAM level prior to shutting down circulation and installation. After installation, I restarted the process until the SLAM completion criteria was complete.

 

[TigerFanatic1]

I'm definitely looking for what I missed and trying to understand a better path forward. I do plan to get family more involved, but looking at the data they provided, there isn't anything I would have done differently, so I would still be in this situation. There is always the chance that there was some light algae on the steps or other early signs and I would have reacted differently. However, looking at the numbers, I believe I should have been safe from it. Even with the estimated 1.1" of rain, should have been around 450 gallons or 1.7% additional water. While losing some due to freshwater, I would have expected the UV to be low and have minimal impact.

 

[Newdude]

So where are we now ? Mid SLAM ?

Have any pics for reference? Still green ?

 

[TigerFanatic1]

So where are we now ? Mid SLAM ?

Have any pics for reference? Still green ?

Added 7 gallons of chlorine yesterday evening and brushed. This morning the FC was down to 10, added 6 more gallons and brushing throughout the day. Pool looked a lot better this morning, with some settlement. Pool wasn't vacuumed, but brushed again. Both pictures are the deep end. Each gallon generally adds 4 ppm if a fresh batch.

 

[Newdude]

Did you pop your light out ? We usually let that one go because it's a pain, but on a repeat slam it is a biggie to check. Was the ladder emptied clean ? (If you have one) each rail can hold a gallon or two. Somebody earlier had the foam of the weir door algae'd up. Every last inch is suspect. And on top of that, it's now been exposed to this bloom and needs a good scrub again.

Any water features ? They need to be run and purged daily.

 

[TigerFanatic1]

I've never removed a light or ladder. I do brush all each time, but have never thought about ensuring the voids under each step is brushed or pulled ladder away from pool to get between bumper and liner. No water features. Would the algae in these areas not be killed with the SLAM level FC?

 

[Newdude]

If you have the old school light, it holds alot of water behind it with next to no circulation. The same with the ladder rails when you pull it and remove the bumpers. Both will allow old pool water to seep out and start a new bloom.

 

[Newdude]

OP posted 2 videos in the first post. Watch the 2nd one where he pulls the algae light out.

Jumped in head first into the deep end with our first pool, thank God I found TFP! (Things I learned about SLAM and Pool Stores)

Quick background: After purchasing a new home that came with a pool, I knew my knowledge was at a solid zero and that I'd need some major help. We turned to the company that the home's previous owners used to open/close the pool which informed us they no longer serviced our area. So I did some...

www.troublefreepool.com

 

[TigerFanatic1]

OP posted 2 videos in the first post. Watch the 2nd one where he pulls the algae light out.

Jumped in head first into the deep end with our first pool, thank God I found TFP! (Things I learned about SLAM and Pool Stores)

Quick background: After purchasing a new home that came with a pool, I knew my knowledge was at a solid zero and that I'd need some major help. We turned to the company that the home's previous owners used to open/close the pool which informed us they no longer serviced our area. So I did some...

www.troublefreepool.com

I don't have that style of light, but do have three smaller lights and the ladder. So while it is newer, there are 3 chances of failure. I'll investigate the ladder assembly also, as I'm not sure how it remove it to inspect. I'm sure the ladder is just a basic stainless or chrome 3 step. Would it be any harm

 

[Newdude]

I'll investigate the ladder assembly also, as I'm not sure how it remove it to inspect

If it's the standard issue one, there are two plates at the base that pop up. Under that is a tension bolt. Then the ladder pops up (with force). I had to use a block of wood and a sledge to give mine love taps and not ding the finish. Post a pic of the ladder and the base if yours sounds different.

I don't have that style of light, but do have three smaller lights and the ladder.

So 4 points of possible old water seeping into the freshly Slammed pool. Post pics of the lights also. If the don't have a screw holding the faceplate in, they may be unremovable and also not a possible problem.

 

[TigerFanatic1]

So 4 points of possible old water seeping into the freshly Slammed pool. Post pics of the lights also. If the don't have a screw holding the faceplate in, they may be unremovable and also not a possible problem.

Thanks for the updates, I'll be away from home for about 6 more days but will check when I get home. Last thing I want is to be buying a new phone when family drops in pool lol. Pool has progressed to the cloudy state and SWG was able to gain some ground with FC, so we will continue efforts. I'll keep the FC up until I get home and can check the ladder and lights.

Would it be any harm in adding liquid chlorine to the skimmers? I was thinking about drilling a small hole in a container and let the chlorine treat the piping over a period of time. Or should the elevated FC levels during SLAM properly treat the piping?

 

[Newdude]

Or should the elevated FC levels during SLAM properly treat the piping

Pipes have constant SLAM water running through them and they are clean.

The pinhole thing doesn't work nearly as well as you think. Me and Mguzzy tried for a member going away and you need a controlled drip with a IV bag like clamp to reach one drop per 10 seconds or whatever the math we came up was. Poking a smal pin hole emptied the jug in 2 minutes. It was great on paper tho.

 

[TigerFanatic1]

I figured it would just end up being a short duration of super FC water. lol