Affect of pollen on free chlorine

[mikefamig]

We are in full pollen season here and my chlorine demand has gone from 2 pints/day a few weeks ago to a gallon or more now. I began to slam the pool but it occurred to me that it may be smarter to wait until the pollen subsides to do the slam. My water is crystal clear and I have zero combined chlorine but I still use 4 - 5 ppm over night. I think that the pollen is going into the water at night as well as in the daytime and using up the chlorine.

What do you guys recommend? Slam now or wait until the pollens eases up. For those of you in dry climates and aren't familiar with how bad pollen can get, I have a yellow powder visible on horizontal surfaces in the pool area.

Mike.

 

[woodyp]

You've got more going on there than just pollen. In season, I swear you can walk on the pollen on my pool water surface, and I've never experienced anywhere near that kind of FC loss.

 

[mikefamig]

You've got more going on there than just pollen. In season, I swear you can walk on the pollen on my pool water surface, and I've never experienced anywhere near that kind of FC loss.

So I'll take that as a vote to slam now.

Mike.

 

[mikefamig]

I just tested the chlorine this morning and it is better.

The pool is 16x32 approx 17k gallons.
Last evening I measured FC=7 and added 4 pints of 12.5% chlorine so I figure it to = ~ 10 ppm.
This morning at 9:30am I measured 8 ppm and added 4 pints of chlorine.


My wife is going to swim this afternoon so I will leave well enough alone for today.

Mike.

 

[woodyp]

What is your "normal water temp" this time of year if you don't heat it? It's kind of a tradeoff between doing a SLAM fighting either pollen or warmer water temps.

 

[mikefamig]

What is your "normal water temp" this time of year if you don't heat it? It's kind of a tradeoff between doing a SLAM fighting either pollen or warmer water temps.

The water temp has been in the low 70's all week. It was at 75deg this morning and now the heater is on. The temperature has been in the low 70's all week.

Mike.

 

[woodyp]

I'd have at it and SLAM it then.

 

[mikefamig]

I'd have at it and SLAM it then.

I'll see what it does tonight and maybe clean it up in the coming week. What I question is why is the overnight chlorine loss down to 1- 2 last night when it was 4 -5 a few days ago? I have not raised it to break point during that period of time.

Mike.

 

[tim5055]

I'll see what it does tonight and maybe clean it up in the coming week. What I question is why is the overnight chlorine loss down to 1- 2 last night when it was 4 -5 a few days ago? I have not raised it to break point during that period of time.

Mike.

Break point means nothing

From the following thread by chem geek - Certified Pool Operator (CPO) training -- What is not taught

Breakpoint Chlorination
The 10x rule for breakpoint chlorination is wrong and only now some industry people are starting to address this as described here and here, though they are still only accounting for the mistake of not considering that combined chlorine already used up a chlorine atom in combining with ammonia and they are not yet considering that there is still a factor of 5 error in their approach since the units used to derive the 10x rule come from chlorine (measured in ppm Cl2) oxidation of ammonia (measured in ppm N) whereas combined chlorine is measured in the same units as chlorine (i.e. ppm Cl2) where the Cl2 units are 5 times higher than the N units (that's the molecular weight ratio between the two). The oxidation of a combined chlorine that is monochlorourea (i.e. chlorine combined with urea) may require 3x, but that still far from 10x. There also isn't any getting "stuck" -- one can just add more chlorine. When one has persistent CC, it is not due to getting "stuck" but from compounds that do not oxidize as quickly. More technical details about this are described in this post.

The handbook has a newer breakpoint chlorination rule, but it is still a "10x" rule, though uses a target FC as 10x of the CC rather than using an incrementally added 10x amount. It incorrectly states that adding less than the breakpoint calculated amount may not achieve breakpoint, not recognizing that the 10x rule is wrong when starting with CC (it's correct when starting with ammonia measured in ppm N units).

We base our system on "Shock FC" which is 40% of the CYA level.

Plus, CC in and of itself is not singularly predictive of bad things happening. We have seen green pools with "0" CC and clear pools with high CC. There are alos some chemicals that interfere with the CC test, like non chlorine shock (MPS). have you used any?

 

[mikefamig]

Breakpoint, shock, superchlorinate, whatever you want to call it, I am talking about the point that combined chlorine is released into the atmosphere. I am calling it 20ppm at 40 - 50 CYA. And nothing more than chlorine, CYA and baking soda have been added to the water.

 

[tim5055]

am talking about the point that combined chlorine is released into the atmosphere.

UV from the sun deals more with CC. Yes, chlorine will eliminate CC but the sun does it better quicker.

CC really doesn't have to be there at all. We have seen total swamps - thick, green with frogs living there that never tested any CC.

Your overnight loss of FC may have gone down because organics in the pool have gone down. We really can't answer that one.....

 

[mikefamig]

Break point means nothing

Plus, CC in and of itself is not singularly predictive of bad things happening. We have seen green pools with "0" CC and clear pools with high CC. There are alos some chemicals that interfere with the CC test, like non chlorine shock (MPS). have you used any?

I am measuring zero combined chlorine.