why algae?

[drrayb]

my wife had a bunch of friends over and swimming all day. i heated the pool to 29 for the ocassion from 24.
the rest of the chemistry was:

FC 8.5 (i always keep it here because we have fairly poor circulation with only 2 jets)
CC 0
CYA 60
TA 60
ph 7.8

after the swim i noticed water level was down so i put the hose in to top up...then shamefully forgot about it and ended up adding too much water.

36 hrs later, algae everywhere, and the values above are unchanged. what happened??

 

[TinFoilHat]

How are you testing the water? What kit are you using? What is the source of your water? City? Well? FC won't fix a circulation problem. Only running the filter for longer hours or brushing the pool will move your chlorine around. How and what chlorine do you use?

 

[drrayb]

How are you testing the water? What kit are you using? What is the source of your water? City? Well? FC won't fix a circulation problem. Only running the filter for longer hours or brushing the pool will move your chlorine around. How and what chlorine do you use?

tfp kit, salt cell, city water. its all i can do. 2 jets in a massive pool. the robot and swimming stirs the chlorine around the dead zones every other day or so. this is the best ive achieved after tinkering for 5 years

anyways, my question was more about why the sudden change. did the new water create some gradient that screwed everything up?

 

[Bperry]

tfp kit, salt cell, city water. its all i can do. 2 jets in a massive pool. the robot and swimming stirs the chlorine around the dead zones every other day or so. this is the best ive achieved after tinkering for 5 years

anyways, my question was more about why the sudden change. did the new water create some gradient that screwed everything up?

Probably need to confirm it’s algae and not metal contamination. That’s the reason for test results and you can do an OCLT to confirm it’s algae or not. Maybe post a picture as well.

 

[PoolStored]

anyways, my question was more about why the sudden change. did the new water create some gradient that screwed everything up?

Heavy FC demand from lots of humans with stuff that needed oxidizing...and dilution of your FC due to adding water, dropping FC low enough to not be able to sanitize. Finally, SWCG was not setup to handle the bather load and the dilution of the FC.

Do OCLT to confirm algae. Link-->Overnight Chlorine Loss Test

You fail, you slam. Link-->SLAM Process