Possible Algae Bloom coming? Should I SLAM?


Well-known member
May 7, 2018
Greensboro, NC
I’m truly at a loss here...This year, we put up an 18’ x 52“ Intex pool (6900g +\-). It’s been up five weeks now. First fill was on the 3rd. I say first because I had to drain about half of it to fix a leg settling issue and refill it. Then, we’ve had monsoons of rain - 14” in ten days. Ugh...

I’ve kept my FC levels appropriate to what pool math app tells me.

yesterday morning before swimming - but I always add my chlorine in evening after sundown - and get it up to 6ppm - and this was around 2pm in direct sun - so I expect some loss.

FC - 5
CC - 0
pH - 7.4ish
TA - 70
CYA was 40/50 - hard to tell - but been using 50 with pool app.
pool temp is a lovely 86 degrees

Pool water is nice and clear and we vacuum it every other day.

Well, last night, while vacuuming - I found one of those stupid bugs that swim in the water. Was only one...a water boatman in looked like since he went all through the water column. Given I’ve read these guys only eat algae - I’m guessing I’ve got a bloom on the way? From what I’ve seen - these guys are natures last warning before my pool turns green... My Intex sand pump shows in the green pressure wise - and I deep cleaned the sand before opening poop this year. I run it 8 hours a day.

1) how the the heck did he get there? Do they just show up somehow?
2) would you suggest a SLAM at this point?

Thank you.


Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
We feel your pain with the weather. 24" last 10 days here. We've got a totally enclosed IG pool and still get all kinds of critters in the pool. Just stay within TFP water chemistry and you'll be fine. Testing a little more frequently than normal during heavy rainfall helps to make sure you don't get out of balance. On the high end of target is never a bad idea just don't go above SLAM level to protect your liner and make sure pool is safe for swimming.