Looks like I am controlling CC easier now

[SPP]

Guys,

I been trying to see if my ozonator can assist in removing CC and what level of FC is best to also help remove CC easily without needing to shock.

For the time being I am looking at the numbers and it looks good so far but bather load not that high yet, I had 2 big rains though. I can not yet profile my pool typical CC production, because I only have TF test kit for a while.

I am wondering if anyone of you have some sort of log book or data to compare with my numbers.

CYA 25PPM PH 7.6 Water Temp 28*C
Pool turnover 12 hours. Pump run time daily minimum 12 hours. 50GPM water flow clean filters.
Pump cycle, 8AM turn on. 8PM turn off.
Ozone level at injector tip = 0.176 PPM at 8.3 seconds contact time estimated within pipes.
Add water to pool daily minimum 400 liters or 106 gallons if there is no rain. There is a minor "leak" somewhere.

Everytime it rains, the worry is not the rain water. The amount of dirt the sun shade is holding is worth the mention and also the building wall that also contribute to the dirt. I can tell how much rain water got into the pool by looking at the water level in the balancing tank with pump running.

27th Aug 08:00AM TC = 2 OTO test
27th Aug 11:30AM FC = 1 CC = 0 FAS/DPD with 0.2 resolution
27th Aug 13:45PM Add 1 liter bleach 12%. Pool calculator stated 1 liter = 0.92 PPM increase

28th Aug 06:50AM FC = 1.5 CC = 0 FAS/DPD with 0.5 resolution
28th Aug 15:00PM Heavy rain for 3 hours. Rain water into pool no more than 200 gallons. Dirt..well always a lot.
28th Aug 18:30PM FC = 1 CC = 0.5 FAS/DPD with 0.5 resolution
28th Aug 18:35PM Add 2 liter bleach, extend pump run time by extra 4 hours or 16 hours total.

29th Aug 08:00AM FC = 3 CC = 0 , FAS/DPD with 0.5 resolution

30th Aug 07:15AM FC = 2.5 CC =0 , FAS/DPD with 0.5 resolution
30th Aug 20:25PM FC = 2.5 CC =0 , FAS/DPD with 0.5 resolution. I believe its cloudy that day

31st Aug 07:00AM FC = 2.5 CC =0 , FAS/DPD with 0.5 resolution
31st Aug 15:00PM Heavy rain for 3 hours and 2 divers using pool for 3 hours. Rain water into pool, max 200 gallons.
31st Aug 20:00PM FC = 1.5 CC =0.5 FAS/DPD with 0.5 resolution
31st Aug 20:20PM Add 2 liter bleach, extend pump run time by extra 7 hours or 19 hours total

Today
1st Sep 07:15AM FC = 3 CC =0 , FAS/DPD with 0.5 resolution
Pump run only at 09:00AM upwards.
I finish writing this report at 10:05AM, 1st Sept 2008
No "chlorine" smell reported by divers and my nose too...

I had once seen my pool peak clarity collapse progressively merely from 4 divers for 3 hours in the water. At the end of the day it was mild cloudy. The TC was 2.5 minimum but I do not know the CC back then. The other cloudy session was because of sudden rain after a long dry spell...so I suppose lots of organic flowed into the pool. I think I had three cloudy session since June 2007 and 2 are from divers and once from rain.

Normal swimmer without dive gear never impacted my pool clarity the way diver do. I think I know why. Dive gear do not get washed the way we washed our swimming wear with soap and all the good things to clean clothes. Dive gears are only rinsed with fresh water and hang out to dry, that's it. It get used in the sea, lie around boat decks and so on. I bet contamination must be high. Dive gear surface area is huge compared to swimming wear at least 5-15 times more, depending if we compared a wetsuit to a G-string..

I do get the dive gears to be rinsed before pool use use and special scuba tanks for pool use only that never get rented out for sea use, but without proper soap wash, technically my pool water is the one sanitizing those dive gear...

I am also thinking to do this :

- Raise 1 PPM FC 1 hour before any divers use the pool or when it starts to rain
- Add another 1 PPM FC after diver used the pool or after a decent 3 hour rain

Which is better, above method or hit 2 PPM FC after use or rain like what I am doing now as soon as I am seeing low level 1.0 to 1.5 PPM FC ?

I rather spend some more $$ on another 2 gram ozonator if it really works the way I think it does, than having to shock my pool. If I need to shock, it will be at least 10-12 PPM FC to be safe. For some reason I do not want anyone to swim in my pool at higher than 5PPM FC, even though I have 25PPM CYA. After shocking a pool and to wait for it to go down to 5PPM FC, it will take me 5-6 days and with good sunlight. I can have trouble if diver training schedule is 2 times a week, let alone 4 times a week. My kids will also make so much noise. The ozone already paid itself in improved clarity, and for indoor pool it said to remove CC well. I am hoping at double dose or 0.35 PPM at the injector tip I can get rid of CC faster or capable of removing higher CC, say 1 PPM CC. I am already enjoying another benefit. No more double pump needed to be run since I have the ozonator. Pump extended run I only do like 4-7 hours extra compared to 12 hours or 18 hours if double pump involved after a big rain.

I have to say that at 3PPM FC and zero CC, there is no "chlorine" smell.
Without TF test kit this would be impossible... to do.
Knowing my pool chemistry better makes me demand even more. Aside from clarity issue, now I am obsessed with killing CC...my my. With greater knowledge comes greater responsibility... I am staying away from public pools for good.

PS.. I finished a bottle of R-0871 in like 2 weeks !!!

Thanks All

 

[chem geek]

In my 16,000 gallon pool, when one person uses the pool every day for about 1 hour, I never measure any more than 0.2 ppm CC, the lowest reading so it could be less than that. When there are two people on the weekend with more swimming, I sometimes get 0.4, but usually it's 0.2. When we have a party with quite a few people in the pool, then it gets to a solid 0.4 with a rare blip to 0.6, but the CC goes away on its own as the breakpoint of ammonia and oxidation of urea happen continually with the maintained FC level. I never shock to get rid of such small CC levels as they go away on their own over time (usually overnight).

In a spa, a useful rule of thumb is that the chlorine demand (from sweat and urine) is around 7 ppm FC in 350 gallons per person-hour. In a pool, it's probably around half that amount. 3.5 ppm FC in 350 gallons is 0.077 ppm FC in 16,000 gallons per person-hour and the amount of FC is 1.5 times the amount of CC that is formed. So in a 16,000 gallon pool, a reasonable rule-of-thumb would be that there is 0.05 ppm CC per person-hour. Of course, CC can form from other organic substances in the water, not just from sweat/urine from people.

0.5 ppm CC gets 90% oxidized in around 4 hours when the FC is at around 10% of the CYA level (this is with no sunlight). Your ozonator can somewhat speed up the process, but not by very much since the time it takes for one turnover of water only has 63% of the water go through the ozonator (it takes 2.3 turnovers for 90% and 4.6 turnovers for 99% of the water to go through at least once). Normal breakpoint of ammonia in a pool where the CC is 0.5 ppm to start with and the FC is 10% of the CYA level is 90% complete in around 4 hours. So perhaps the ozonator might improve this time a little down to 3 hours, but probably not much more than that.

If you sweat, then when you get out of the water your additional sweat combines with chlorine in the water on your skin to form more monochloramine so can have your skin smell a little. An ozonator doesn't help for that effect at all. Only a lower FC might help as it will "run out" early at which point ammonia/urea in your sweat just remains unoxidized on your skin.

If you are really concerned about absolutely minimizing chlorine smell, including that on your skin, then the way to do that, at extra expense, is to use a supplemental algaecide (PolyQuat 60 or phosphate remover on a regular basis or 50 ppm Borates) and then use a lower FC/CYA ratio -- most likely having the CYA be high since you need some FC to not run out. So in a 10,000+ gallon pool, having 2 ppm FC with 80 ppm CYA would probably be the lowest you could go, but would need the algaecide to prevent algae growth. This situation is still sanitary since bacteria, viruses, etc. are much easier to kill/inactivate than algae. However, all of this comes at an extra cost for the algaecide (unless the 50 ppm Borates are sufficient since that's mostly a one-time cost). The downside to this approach is that oxidation of ammonia/urea and organics is slower (so CC's would normally persist longer), but that's where your ozonator can partially make up for that. At even more extra expense, one can use a non-chlorine shock which will oxidize ammonia/urea with no smell and no formation of combined chlorine, but it interferes with the chlorine test readings (especially CC) and needs a special reagent to remove interference.

Richard

 

[SPP]

Thank u very much Richard.
This is the kind of answer I am expecting... ...in-depth...

I will swallow this slowly. I must polish my CYA/FC chart.

There is no Poly60 in my country, so that is out of the question.
I have to check the available industrial version of phosphate remover and the Borates.
I did surf on Poly60 chemical name but could not find much. The Borates I think I know what they call it locally but I must check again properly because I believe it is like formalin or something ???? I mean I heard some people actually use this to preserve food. There are whacky things going around in 3rd world country u know. Irresponsible devils are pretty hungry for $$. I have to be very careful with chemicals here.

My back up pump on trolley can do 8 hours turnover, its my estimate. I have not install a flowmeter yet because the straight pipe is not long enough for the meter installation requirement, but I will try nevertheless to install it. I have a spare.
If I can do away with chemicals that I have to buy, I rather get another 2 gram ozonator to be placed on my back up pump on trolley. This way with both pumps on, I can do approx 5 hours per 1 turnover. I can keep an increased FC at constant 2.5 since I can't smell it and the diver reported no smell + no harsh feeling on their skin....that's what I feel too.

My weakness now is still the slow circulation of 12 hours if only main pump on. Fast clarity recovery need fast pumping too. So I get filtration benefit too if both pumps running. 5 extra hours on both pump is a short time, easy to do. The trolley pump is of a good flow because no long piping, its all hoses, 33' suction and 36' outlet. The only thing I will loose is ozone contact time. Maybe I can buy that small ozone chamber that DEL has.

What do you think ?
Honestly I rather pay up front money on extra equipment and not needing to buy various chemical that I probably can't even get its MSDS.

Thanks again.

 

[chem geek]

I want to emphasize that I'm not recommending the things I mentioned, such as algaecide (except perhaps 50 ppm Borates) and MPS non-chlorine shock. I'm not sure why you can't live with the very low level of CC and faint chlorine smell.

As for water clarity, good circulation plus microfiltration works best which is why DE filters are good (as are sand with a small amount of DE added). However, you can also use something like The Slime Bag.