Algae/Boatman/Backswimmers

[Laker]

We've been struggling with keeping backswimmers out of our pool. Everything we read says algae leads to boatman which lead to backswimmers. We are very new pool owners (installed late August) and had been taking advice from the pool store guys until earlier this week when we found this site and forum. We've been reading constantly and feel like we have a decent grasp on most of the basics but still very unsure we'll be able to correct our issue. Although we have never seen visible algae, we are assuming it's there because of the constant infestations of boatman and backswimmers. We are currently performing Overnight Chlorine Loss Test but the plan is to start a SLAM tomorrow regardless of the result. But when reading on the SLAM process, our current CYA level of 20 would require us to elevate our FC to 10ppm. We just started monitoring our CYA level as our pool store guy originally told us our chlorine pucks had all the stabilizer we would need. Obviously not true because we had been at 0ppm but now have been able to raise to 20 with stabilizer. So we're getting there. Getting back to SLAMing the algae, based on our CYA level of 20, our recommended SLAM FC level is 10ppm. The concerning part about this is that we double shocked (pool store shock) 3 nights ago and our FC test tonight was 10.5. So isn't this the equivalent of SLAMing based on our low CYA level? And if we've technically been unknowingly SLAMing for 3 days now, shouldn't we be seeing some results with the algae/boatman/backswimmers? Or is our CYA just too low and the corresponding FC recommendation just not enough to kill the algae? If so, is there a standard minimum FC level needed to kill algae regardless of CYA? Obviously our heads are spinning and any input is greatly appreciated

 

[Wobblerlorri]

Your CYA is too low to support an effective SLAM level. Bring it up to 40 ppm, then SLAM at 16 ppm FC. Net out all the bugs you can find and transport them far away from your pool. Then scrub really well along the waterline, which is where they lay their eggs.

You're getting close to closing time, unless you heat your pool, so once you pass OCLT go ahead and close the pool.

You probably have such a bad backswimmer/boatman issue because the darn things are predators. They eat each other and they're cannibals, so even if the algae's gone, they still have plenty of food.

 

[Laker]

OCLT passed last night.

FC: 10.5
CC: .5
pH: 7.0 (currently aerating to bring up)
TA: 130 (adding acid to lower)
CYA: 20

So does this mean no algae? Attached is a pic of what we see on our pool floor consistently. These light gray deposits seem to turn brown after a few hours.

So based on our OCLT, should we just close the pool now? Or is chlorine too high for that? Or is there anything we need to adjust with our levels yet before closing? As new pool owners, we really want to make sure we do everything right when closing to avoid opening to issues next spring.

 

[Mdragger88]

Leave your ta alone- aerating to bring ph up is fine but u will tank the ph by adding acid now.
Ph results are innaccurate @ fc levels over 10ppm.
which is why it’s suggested to bring ph to 7.2 before u begin.
What kit are u using?
you should bring the cya up to 30 or 40 like @Wobblerlorri suggested & then slam.
As reading a cya of 20 isn’t real accurate.

What you are seeing is algae that’s growing & then being killed by the chlorine. That’s why we recommend a SLAM Process with liquid chlorine so you are constantly hitting it as it fights back.(the more frequently the better) Vs a 1 time shock that just clears it temporarily & then it returns.

 

[Laker]

Leave your ta alone- aerating to bring ph up is fine but u will tank the ph by adding acid now.
Ph results are innaccurate @ fc levels over 10ppm.
which is why it’s suggested to bring ph to 7.2 before u begin.
What kit are u using?
you should bring the cya up to 30 or 40 like @Wobblerlorri suggested & then slam.
As reading a cya of 20 isn’t real accurate.

What you are seeing is algae that’s growing & then being killed by the chlorine. That’s why we recommend a SLAM Process with liquid chlorine so you are constantly hitting it as it fights back.(the more frequently the better) Vs a 1 time shock that just clears it temporarily & then it returns.

Thank you for responding. This makes sense. But the confusing part is the OCLT. Shouldn't we have seen a loss in free coloring if we're dealing with algae?

 

[Mdragger88]

Also please add your signature it helps us help u

Create Your Signature - Further Reading

www.troublefreepool.com

 

[Laker]

Leave your ta alone- aerating to bring ph up is fine but u will tank the ph by adding acid now.
Ph results are innaccurate @ fc levels over 10ppm.
which is why it’s suggested to bring ph to 7.2 before u begin.
What kit are u using?
you should bring the cya up to 30 or 40 like @Wobblerlorri suggested & then slam.
As reading a cya of 20 isn’t real accurate.

What you are seeing is algae that’s growing & then being killed by the chlorine. That’s why we recommend a SLAM Process with liquid chlorine so you are constantly hitting it as it fights back.(the more frequently the better) Vs a 1 time shock that just clears it temporarily & then it returns.

We are using the TF-100 kit. Just got it yesterday though.

 

[Mdragger88]

Thank you for responding. This makes sense. But the confusing part is the OCLT. Shouldn't we have seen a loss in free coloring if we're dealing with algae?

Not necessarily- you said u have visible algae- this requires a slam.

 

[Laker]

Not necessarily- you said u have visible algae- this requires a slam.

We have not seen any algae attached to the walls and we are just assuming the powdery deposits that gather on the floor is dead algae but we are not sure

 

[Mdragger88]

It’s best to err on the side of caution - basically when in doubt slam..
All you have to lose is the water boatmen, algae, and some liquid chlorine.
there really are no other magic solutions.

 

[Mdragger88]

Dead algae was alive at some recent time...
you slam until there’s no more dead algae

 

[Mdragger88]

dead algae on the floor is not clear- aka- you’re not done.
probably won’t take long though. Lots of folks pass their oclt & still have this.
Maintain until u have no more “new” dead algae. Brush & vac daily with the filter running 24/7 until the floor remains clear.

 

[Laker]

View attachment 163971
dead algae on the floor is not clear- aka- you’re not done.
probably won’t take long though. Lots of folks pass their oclt & still have this.
Maintain until u have no more “new” dead algae. Brush & vac daily with the filter running 24/7 until the floor remains clear.

We really appreciate all your help. Want to mention it is really dry in our area and crops are being harvested all around us. The air is very dusty and blowing around a lot. So I'm thinking there is also a lot of dust and debris flying into the pool making it tough for us determine when the algae is completely gone from the bottom.

Regarding vacuuming, would you vacuum through to filter or vacuum to waste? If going to filter, do you recommend a skimmer sock to catch all the small dead algae particles?

 

[Mdragger88]

Dust won’t turn white/gray - algae does that so let that be your guide. Vac to filter is fine- backwash when pressure rises 25% over clean pressure. Skimmer sock is fine too!
i see now that u have an above ground pool. Pull steps/ladder & scrub them also if u have a light niche scrub it too. Check skimmer throat & weir door foam. These are known places that algae hides.
U want total eradication!

 

[Mdragger88]

Funny story .... i had a slight haze to my water earlier this summer so I decided to slam. Things looked great but i still wasn’t passing the oclt w/ flying colors & i had recurring dead algae in a couple places. I was scratching my head but just kept slamming. Well, the kids had left one of those diver things that lights up in the pool & just left it (the automatic vac would push it around) I figured the chlorine would take care of it. Wrong... i got in & fished it out & the little dome that holds the light was filled with algae!! I threw it away so mad at myself for leaving it in for a week.
That night i passed my oclt. A day after - no more stuff on the floor! I still held slam for one more day to be sure.
So trust me, check everything, even if u think it doesn’t matter.

 

[Laker]

Funny story .... i had a slight haze to my water earlier this summer so I decided to slam. Things looked great but i still wasn’t passing the oclt w/ flying colors & i had recurring dead algae in a couple places. I was scratching my head but just kept slamming. Well, the kids had left one of those diver things that lights up in the pool & just left it (the automatic vac would push it around) I figured the chlorine would take care of it. Wrong... i got in & fished it out & the little dome that holds the light was filled with algae!! I threw it away so mad at myself for leaving it in for a week.
That night i passed my oclt. A day after - no more stuff on the floor! I still held slam for one more day to be sure.
So trust me, check everything, even if u think it doesn’t matter.

Yikes. That is good to know.

Since we got our pool, I've been worried about damaging the liner with too much chlorine. Is that a myth or something we need to consider when slamming?

 

[Mdragger88]

That is the reason for the FC/CYA Levels. It is safe to swim up to slam level for your cya & also safe for your liner & equipment. Damage occurs when people don’t know their cya (or other parameters) & blindly dump chems in without knowledge of what their effects will be .
That’s not how TFPC operates.

 

[Mdragger88]

Here’s another helpful explanation;