Green Pool / fighting it all summer

Jun 17, 2015
4
Springdale/AR
I've been trying to get on board with the BBB method but I've been fighting this pool all summer. I've had the pool clear several times over the summer but it nearly always goes back to light green with an algae bloom. Doesn't seem to matter what I do or how much chlorine is in the pool either. I need some help. Below are the current results from testing.

Ph=7.2
FC = 6.5
CC = 0 (why is this?)
CH = 75
TA = 40
CYA = 60

I'm pumping dollar after dollar into chlorine and tests kits and I can't get it straight. I have a fiberglass pool. I backwash as frequently as I feel I need to, which is often because of the frequent algae blooms. I kill an algae bloom, keep the chlorine levels steady and it it goes green again after a week. Then i'm back to step 1 to SLAM again. I'm tired of SLAMing this pool. I'm ready to order 8 tons of dirt. My kids love to swim so I haven't ordered it yet. :p Any advice is appreciated!

Thanks,
John
 
What test kit are you using?
The CC ideally is zero.

Are you passing all 3 criteria to stop the SLAM process?
If you maintain adequate FC for your CYA level, algae can not grow. Period.
 
+1 what jblizzle said. There is no magic in what we do and your water is made up of the same H20 as everyone.

If you follow our somewhat strict guidelines, you will not get algae.

(BTW, it'll cost a lot more than you think to fill it in. Over 100 yards (about 150 tons) of dirt to start)
 
John, I too have a FB pool and I'm in my 2nd season with it. My first season was a mess halfway though, always sweeping-up green dust, etc. I always thought my test readings were good based on the pool store or local (small) test kits, and tried everything on the market .... until I committed myself to TFP and did a thorough SLAM. I've never had an algae bloom since, and the floor and walls of our pool are squeaky clean, not slimy or slick. I have the TF-100 test kit, and always maintain my FC slightly above my FC target level based on the Pool School - Chlorine / CYA Chart, and my water stays crystal clear in this horrid TX heat. The only thing I can imagine in your scenario is that while you may have been able to get your water "clear" each time before, the remnants of the algae/organics were not completely destroyed - hence the questions above about what test kit you are using and did you actually pass all 3 SLAM criteria. We're forced to ask those questions because so many forum members/visitors believe whole-heartedly that they SLAM'd properly, when actually they skipped one step, or didn't truly pass the OLCT or something else. TFPC methods are proven to work, but if you have any doubts about a particular issue, let us know and we'll try to clear it up for you.
 
What about lights, ladders, steps? Are you scrubbing all the algae away?
What FC level did you target during your SLAM?
How often did you test and add chlorine?
How often did you brush?
How long did you SLAM?
Maybe wait to pass 2 OCLT before stopping?
 
Giving the benefit of the doubt that you followed the SLAM instructions perfectly, could it be that somebody is tossing algae-laden pool toys back in the pool afterwards? A pool noodle soaked in green slime water and then put back in the clean pool could do it. Or trapped water in some inflatable liferaft toy. A squirt gun with a green tint from all the algae inside the reservoir. How about a bubble-wrap pool cover? If it's wet with algae water and gets folded up and left in the sun, that stuff is gonna thrive. And then when it gets put back on the pool, here we go again.
 
What test kit are you using?
The CC ideally is zero.

Are you passing all 3 criteria to stop the SLAM process?
If you maintain adequate FC for your CYA level, algae can not grow. Period.

I'm using the TF-100 test kit. I felt like I passed the SLAM test several times to get the pool clear again and again. It just won't stay that way. I've scrubbed the pool, ladders, lights and toys (but not all toys). I would expect whatever FC levels I'm maintaing would kill risidual algae on toys?

--
John

- - - Updated - - -

+1 what jblizzle said. There is no magic in what we do and your water is made up of the same H20 as everyone.

If you follow our somewhat strict guidelines, you will not get algae.

(BTW, it'll cost a lot more than you think to fill it in. Over 100 yards (about 150 tons) of dirt to start)

I smiled when I saw your comment on H2O -- how true. I know I'm missing something -- just wish I could find it the issue.

150 tons of dirt?! Wow, you're right, it'll probably be less $$$ to figure how the algae issue!

--
John
 
I know I'm missing something -- just wish I could find it the issue.

There is little doubt in my mind there's that one small step that is being overlooked along the way and we're here to help you find that small step. Regardless of the issues you've had earlier this year, let's go ahead and work on the current issue at hand. For starters, what does you water look like right now? If you're able, can you please post a current photo of the water so we're all on the same page concerning the water clarity? Help posting photo's can be found in the posting photo's tutorial.

We'll get to the bottom of this issue! Promise you!!!
 
Lets start all over like you have never done a SLAM...............Here is the FC/CYA chart.

Pool School - Chlorine / CYA Chart

With a CYA of 60 your FC should be MAINTAINED at least 24. It should NEVER go below 24 at any time during the slam. That means you might have to push your FC up over 24 if you will not be there for a few house for things like work LOL.

Now the next step is the OCLT. Here is the link for it.

Pool School - Perform the Overnight FC Loss Test (OCLT)

THIS test will show if your have REALLY finished the SLAM.

Let us know the results of this test when you do it. Go as far as to tell us what time you did the two tests. pm and am.

Does your pool have it's own toothbrush It should. It should be used all around the skimmer basket especially under it and inside where you cannot really see. Use it all around the returns. Take out your ladder if at all possible and use it on that.

Post ALL of your test results including times when the tests are done. We might be able to see a pattern that you are not seeing.

Kim
 

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I'm in as a cheerleader! It's good that you're asking and answering questions. The more info you can give here the quicker we can all figure this out!

There are lots of problem solvers here and everyone's ready to help troubleshoot!

So here's a pat on the back from me and a "way to go!" for being willing to ask for help and give the info needed to help with the troubleshooting.

Step by step we'll get it figured out and you can get back to enjoying a crystal clear pool!
 
Hello, John.

I agree you need to complete a thorough slam, carefully recording your results, giving the overnight chlorine loss two nights, and ensuring that that Your slam Level never drops below 24 provided your cya is still reading at 60 when you start.

However, what I wanted to comment on was a few notes about what's happening between slams. If in fact your pool is turning green a week after your slam, there are two possibilities:
1. Residual algae slowly fought its way back because it had not been eradicated during the slam, meaning the slam was not long enough in the "kill" zone. This has been addressed.

2. Your regular FC is not being maintained high enough during routine maintenance. It takes algae about 3 days to grab hold, roughly speaking. Going green again a week later suggests that by the fourth days after the slam, your regular FC even is not high enough.

Bearing in mind that the cya test is only accurate plus/minus 15, after your next slam, you may wsh to bump up your daily FC levels to the ratio for 70 cya (please click in the chlorine cya chart link in my signature to review levels.)

Only you can know, testing daily, preferably at the same time, what your FC has dropped to when you dose again. But here's how it works in my pool.

At 35 cya, rounded up to 40, I am supposed to target 3 - 5 ppm. But by charting my pool, with high temps and high organic load from surrounding terrace, I instead target 4 - 6 ppm because I know I can "use up" about 3 ppm per day.

That means at the min., I dose daily to get to 7 or 8 ppm -- to account for the fact that I might lose 3 ppm or more, and that cya is imprecise, and that its possible (though rare) that something could happen and I would miss a day.

The net effect of this is that in MY pool, technically I am "riding" the HIGH range for 40 cya of 5 ;) even though it might drop as low as 3...but only by dosing at the next level recommended for 50 cya.

This is way simpler than it sounds, but I wanted to walk you through the logic because I've noticed that some people will dose just to the high number in the range, but that doesn't account for actual and unique pool consumption ;)

If your goal, at 60 Cya, is to never fall below 5, then be sure to dose in a way such that 24 hours later when you dose again, your FC reads at east 5 BEFORE you add your chlorine. Then add to 8 or 9, depending on your average pool use.

Hope that helps you get the hang of it moving forward post-slam.

Otoh if you've NEVER dropped below 5 and this continues to happen, then your slam is not being completed fully, you have algae hiding behind the light, etc. because once algae has taken hold, 5-8 isn't going to touch it...only Slam level at 24 in your case...and never below 24 at 60 cya, is gong to effectively kill it!
 
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