Water bug Infestation

[Jeffnhelen]

I recently went on a week long vacation and came back to clumps of black under the water. Upon closer inspection, I realized the clumps were dozens maybe hundreds of . I did a quick Google of what could cause the mass infestation and most of what I saw was algae related. I made sure to check the levels before I left and my readings were FC 6.5 / CC 0.5 / PH 8.0 / CSI -0.07. I did dump some MA to bring the PH back down to 7.4 while I was gone. The readings after I got back were not much different FC 7.5 / CC 0.5 / PH 8.1 / CSI -0.03. So based on those levels I’m not sure it indicates I have a algae problem, although I haven’t been as diligent on my maintenance due to my schedule and the weather.
I have run my robot and did a couple sessions of running the skimmers on high to try and collect the boatmen and now back swimmers so the pool is pretty much clear at this moment, but here is what the skimmers collected:

 

[Texas Splash]

Hard for me to tell exactly what all in in that mixture of debris. I would be surprised if you had any algae this time of year with the chilly water and good chlorine level. I do notice right away that you don't seem to be using a skimmer sock in the skimmer basket. So I would encourage that right away as it helps make cleaning a bit easier. I don't see all of your test results posted above, so if you chose to post another round of numbers, I would recommend posting like this:

FC
CC
CYA
PH
TA
CH

that makes it a bit easier for us to evaluate. As for the debris, you may just be in an awkward period of wind, bugs, and debris hitting the water. But let us know if things get worse or if we can help any further.

Also see: What kind of Skimmer Sock do you use?

 

[Donldson]

Really hard to make much out in the pictures, but offhand those don't really look like water dwelling bugs to me. Most water bugs don't get caught in the skimmers because they can swim, it's the flying bugs that try to land on the surface of the water that get caught up in the skimmer.

This looks more like something I would expect from a swarm of bugs flying by, a few dozen land on the water and get trapped, and the swarm flies on leaving their fallen behind.

 

[Newdude]

I got two guesss for you.
1) they hatched and fell out of a tree (along with those leaves) and drowned
2) some sort of pill bug living in nearby mulch or under the patio. Rain may have forced them up like earthworms and they fell into the pool trying to escape the rain/puddle

 

[Oly]

Take some close up pics of the critters.
A pool is an effective insect trap (leaves, dirt, rodents too) so if migratory populations are nearby they will find their way into your water.

 

[Jeffnhelen]

I failed to take a picture as it was dark, but when I first found them they were cling to the walls of the pool and swimming around under the surface. I was surprised that so many eventually ended up in the skimmers also, but I did corral a decent amount into there with my net. I also did dump some of my robots collection in there, so there were pillbugs and scorpions mixed in as well, but the vast majority was boatmen.

 

[Jeffnhelen]

Hard for me to tell exactly what all in in that mixture of debris. I would be surprised if you had any algae this time of year with the chilly water and good chlorine level. I do notice right away that you don't seem to be using a skimmer sock in the skimmer basket. So I would encourage that right away as it helps make cleaning a bit easier. I don't see all of your test results posted above, so if you chose to post another round of numbers, I would recommend posting like this:

FC
CC
CYA
PH
TA
CH

that makes it a bit easier for us to evaluate. As for the debris, you may just be in an awkward period of wind, bugs, and debris hitting the water. But let us know if things get worse or if we can help any further.

Also see: What kind of Skimmer Sock do you use?

I didn’t run the full gamut before I left, but the results from yesterday were:

FC 7.5
CC 0.5
CYA 90
PH 7.8
TA 70
CH 450

Also
Salt 3000
Temp 55F
CSI -0.29

 

[Texas Splash]

Okay, your numbers overall are not bad. CYA on the upper side, but should fall a bit over the winter, and not a contributor to what you're seeing. Those look a bit like Boatman bugs to me. Not sure why you're seeing so many this time of year. Just an odd thing perhaps. But other than the occasional swarm we see 2-3 times per year, they should go away soon.

 

[Jeffnhelen]

Okay, your numbers overall are not bad. CYA on the upper side, but should fall a bit over the winter, and not a contributor to what you're seeing. Those look a bit like Boatman bugs to me. Not sure why you're seeing so many this time of year. Just an odd thing perhaps. But other than the occasional swarm we see 2-3 times per year, they should go away soon.

Only had the pool for a little over a year, but haven’t had a swarm before. Usually it’s just a dozen or two that I take out with the net every once in a while. Just odd indeed as the community pool is within earshot of ours and don’t see any in there.

 

[Oly]

Are you near any open water, rivers, ponds, lakes, etc?
Boatmen are herbivores so unless you have water plants or algae they made a fatal mistake swimming in your pool.
Amazing swimmers and SCUBA divers too.
https://www.bugfacts.net/water-boatman.php

 

[Jeffnhelen]

Are you near any open water, rivers, ponds, lakes, etc?
Boatmen are herbivores so unless you have water plants or algae they made a fatal mistake swimming in your pool.
Amazing swimmers and SCUBA divers too.
https://www.bugfacts.net/water-boatman.php

There is a lake a couple miles from us and a creek bed right behind the fence that only fills up when it rains. Same runs next to the community pool also so still curious why they chose mine. Either way, I will keep an eye on it for the next few days, but vast majority has been killed with a bottle of spray bleach while in the skimmer baskets.

 

[kimkats]

We had a "hatching" late summer here. I saw one or two then a couple of says later they were EVERYWHERE!!!! I took my FC up to SLAM level and had the pump on high to help filter them out of the water. It took 3 at SLAM level to get them all DIED. We even took the steps out to see if there was any algae hiding in them........nope. So we think we just had the bad luck of a couple turning into many more quickly.

 

[Chuckiechan]

We all them boatmen because of the oar like legs. I see a couple a year and then the chems kill them (borates).

With an infestation as big as yours, you might want to come out various times late at night/early morning to see if you can tell where they are coming from. You may have inadvertently created habitat somewhere in your landscaping.

 

[Jeffnhelen]

We had a "hatching" late summer here. I saw one or two then a couple of says later they were EVERYWHERE!!!! I took my FC up to SLAM level and had the pump on high to help filter them out of the water. It took 3 at SLAM level to get them all DIED. We even took the steps out to see if there was any algae hiding in them........nope. So we think we just had the bad luck of a couple turning into many more quickly.

Kim - sorry to hear this happened to you too but comforting that I wasn’t the only one to experience this oddity! Just glad it didn’t happen during the swim season.

 

[QueHales]

If they are the same insect that we call water boatmen here in Arizona, they are air breathers that come to the surface periodically to refresh the air pocket they carry along their undersides. When removed from water, they "fluff out" their wings and fly to new horizons...
In my experience, the four to ten ppm level of chlorine common in desert southwest pools and spas is not sufficient to harm them.
Adding about a half-cup of liquid dish soap to the pool will generally be sufficient to drown them all, as the surface tension is decreased sufficiently to collapse their air supply...