The life of an algae in a well balanced pool

[jetola]

So, i was wondering - and maybe my wonderings can be answered by all you smart people.

This is how i understand the life-cycle of an algae in a well-balanced pool. With well-balanced i mean perfect balance in all parameters, FC - TC - CYA and PH.

1. An algae-spore is carried by the wind, and lands in your pool, or is delivered to your pool through leaves and other organic material that lands in your pool.
2. It tries to grow and multiply, using the power of the sun and the water.
3. However, the FC in the pool attacks it and i cannot grow much. It dies (and its few children dies) - and floats around dead in your pool.
4. At some time, the cirkulation pump starts, and the dead algae is sucked into the skimmer and gets pinned in the sandfilter and now lies with all the other dead algae in the filter.
5. At some point a backwash is done of the filter - and all the algae corpses are flushed out into the drain.

Is this an correct assumption of the life-cyckle of an algae in a well-balanced pool ? ..or does the chlorine work in another way ?

 

[setsailsoon]

Jet,

Welcome to TFP.

Your description is one way that some of the algae cycle in a chlorinated pool is removed. Some also has the cell wall broken in the pool and the cell contents are dumped into the water where the organic compounds are fully oxidized. This also happens to some of the cells trapped on the filter if it is not cleaned and removed before being fully oxidized. The percentage of removal of physically dead cells and completely oxidized cells depends on the pool, maintenance practices etc.

It's been many years since I looked at this in detail. The intermediate chemistry is actually fairly complex and includes the formation of all kinds of aldehydes, esters, ketones and other volatile organic compounds that can evaporate directly before becoming completely oxidized. Pretty interesting if you are designing treatment systems but not really relevant to practical pool water balance.

Why do you ask this question?

Chris

 

[jetola]

Jet,

Welcome to TFP.

Your description is one way that some of the algae cycle in a chlorinated pool is removed. Some also has the cell wall broken in the pool and the cell contents are dumped into the water where the organic compounds are fully oxidized. This also happens to some of the cells trapped on the filter if it is not cleaned and removed before being fully oxidized. The percentage of removal of physically dead cells and completely oxidized cells depends on the pool, maintenance practices etc.

It's been many years since I looked at this in detail. The intermediate chemistry is actually fairly complex and includes the formation of all kinds of aldehydes, esters, ketones and other volatile organic compounds that can evaporate directly before becoming completely oxidized. Pretty interesting if you are designing treatment systems but not really relevant to practical pool water balance.

Why do you ask this question?

Chris

Hi Chris
Thanks for your elaborate answer !

I bought my House 6 months ago with the pool, and opened the pool here in May. So - im a new pool owner. Finally now - with the help of all in here i have crystal clear water - with very little Daily maintenance. Still - every morning after the pump have run at night - i have small piles of dead algae on the pool floor. They are easily removed with the battery driven catfish vacuumer i got. My water is well balanced i beleive (PH 7,5 - FC 6,1 - TC 7,4 - CYA 35 - TÁ 110) and have been so for many weeks.

as i only have a surface skimmer and 1 Return Line and no bottom Drain, i assume everything is at it should be. It is dead algae - killed by the FC just not sucked ito the filter due to the poor cirkulation I have, with only 1 Return Line to create cirkulation - and only a surface skimmer.

yout answer strengthend that assumption

 

[jetola]

My assumption is also build on that the small piles are always at the same spots and if i chance the direktion of the Return Line (creating af different cirkulation) then the piles of dead algae comes in other places. So - it must be cirkulation “dead-spots” in my pool where they are allowed to sink and gatter in small piles.

 

[wireform]

Jet,
You say you have small piles of alage on the the floor.....you also say the FC is 6.1 and the TC is 7.4. If you do the math you have a CC of 1.3 which means there is something going on in the water. I would recommend OCLT to see what's going on and possibly do a slam.

 

[jetola]

Hey
I know the CC is a bit high - though not critical. I have slammed, twice, since May - and the result is the same. Crystal clear water, but still small piles of algae on the floor Every morning. CC has always been above 1 but no chlorine smell. The sides on my pool are metal, and there are some indikations of rust various places - which indicates a leak. A bucket test did show a leak of around 4 liters pr hour. (200 liters pr 48 hours) - which could also cause the issues. I havnt come around to try and fix the leaks (which i assume is around the rust areas)

 

[MITBeta]

Sounds like you fail 2/3 criteria for SLAM completion: clear water, including what's on the bottom, and CC above 0.5ppm.

 

[duraleigh]

Dead algae on the pool floor is symptomatic of live algae in your pool water. Time to SLAM the pool.

My take on the "life cycle" is that in adequately chlorinated water, the algae spores simply cannot develop any further so there should be no dead algae on your floor because there shouldn't be any live algae to begin with.

I do not know this factually, but it makes sense to me.

 

[setsailsoon]

Hey
I know the CC is a bit high - though not critical. I have slammed, twice, since May - and the result is the same. Crystal clear water, but still small piles of algae on the floor Every morning. CC has always been above 1 but no chlorine smell. The sides on my pool are metal, and there are some indikations of rust various places - which indicates a leak. A bucket test did show a leak of around 4 liters pr hour. (200 liters pr 48 hours) - which could also cause the issues. I havnt come around to try and fix the leaks (which i assume is around the rust areas)

Jet,

Just to clarify, one of the nice features about TFP is there's no guessing. If you have a criteria that indicates a SLAM you need to SLAM. When you meet the criteria for completion it's done. CC "a bit high" is not going to get better by itself it's just going to get worse and be more time-consuming to SLAM. A very important difference between SLAM and shock is a SLAM is a process not a one-time event to get to a given FC level. That's why it works and shock often does not.

The mechanical problems with your pool could definitely challenging. TFP methods are designed to work with the reality that pools are always "under attack" from airborne and other sources. You may just need to do a little more frequent testing.

I hope this helps.

Chris