Questions about algae. Question about chlorine consumption.


Silver Supporter
Aug 8, 2009
Bloomington, IL
Algae Questions
1. Where does algae come from in a pool?
a. Does it have to be carried in on something?
b. Or does it develop in the pool on its own?
2. Are the ingredients for algae always present? In other words, if the free chlorine falls below the minimum necessary level will algae always develop?

Chlorine Consumption Question – If we could develop an experiment where two pools are absolutely identical in all respects except free chlorine level, would the consumption be identical? Assume one pool has a FC level of 10 and the other has a FC level of 5. Everything else is identical – same location (side-by-side), same amount of sunlight, same measurements for CC, pH, TA, CA, CYA.

If the pool with FC = 10 loses 2.5 ppm in a given period of time, would the pool with FC = 5 lose 2.5 ppm, likewise? Or would both pools lose the same percentage of FC (25%)? In other words, 2.5 ppm for the pool starting with 10 ppm and 1.25 ppm for the pool starting with 5 ppm.

Answers to these questions will help me better understand my pool.



Mod Squad
LifeTime Supporter
TFP Expert
Apr 18, 2010
East Texas
Re: Questions about algae. Question about chlorine consumpt

Algae "spores" are airborn and can turn into an algae "bloom" in any untreated water. Any excess FC above your target level for your CYA level will burn off at a faster rate in heat and daylight is the short answer.