Swg Producing Red Rash And Burning Eyes?

[Gavin]

is this possible?

my readings are:

FC: 4.5

pH: 7.8

TA: 110

CYA: 70

last week I turned the generator up to 80% as more people are using the pool and its hotter. thought turning it up from 70% to 80% would compensate for more usage of FC.

but do you think the chlorine from the SWG coming out of the jets might be too high and passing in front of the jets could cause a red rash and burning eyes?

[polyvue]

is this possible?

my readings are:

FC: 4.5

pH: 7.8

TA: 110

CYA: 70

last week I turned the generator up to 80% as more people are using the pool and its hotter. thought turning it up from 70% to 80% would compensate for more usage of FC.

but do you think the chlorine from the SWG coming out of the jets might be too high and passing in front of the jets could cause a red rash and burning eyes?

Gavin,

I think that is extremely unlikely. The hypochlorous acid produced by the SWG is just not high enough in concentration to cause the symptoms you describe. I suppose you could test this by turning on the pump, increase the SWG to 100% and take several samples right at the return and measure the FC. That should give you some peace of mind. I presume this is an outdoor pool.

Do you have a FAS/DPD chlorine test at your disposal? You can acheive a very accurate reading of Free Chlorine and, importantly, Combined Chlorine (CC), which ideally shouldn't be more than about .5 ppm. There may be other contaminants in the water that could contribute to red eyes etc but if the pool is being filtered so the water is clear, vacuumed, etc, the FC kept at the level you report, then I wouldn't worry. It doesn't take much chlorine to kill microorganisms in a short time, but it takes a considerable concentration to produce rashes.

Also, kids tend to open their eyes under water more than adults and that could provide some irritation after a long swim. But I think the relatively high salt level of a pool equiped with a SWG is actually more comforting to the eyes.

Greg

[Gavin]

is this possible?

my readings are:

FC: 4.5

pH: 7.8

TA: 110

CYA: 70

last week I turned the generator up to 80% as more people are using the pool and its hotter. thought turning it up from 70% to 80% would compensate for more usage of FC.

but do you think the chlorine from the SWG coming out of the jets might be too high and passing in front of the jets could cause a red rash and burning eyes?

Gavin,

I think that is extremely unlikely. The hypochlorous acid produced by the SWG is just not high enough in concentration to cause the symptoms you describe. I suppose you could test this by turning on the pump, increase the SWG to 100% and take several samples right at the return and measure the FC. That should give you some peace of mind. I presume this is an outdoor pool.

Do you have a FAS/DPD chlorine test at your disposal? You can acheive a very accurate reading of Free Chlorine and, importantly, Combined Chlorine (CC), which ideally shouldn't be more than about .5 ppm. There may be other contaminants in the water that could contribute to red eyes etc but if the pool is being filtered so the water is clear, vacuumed, etc, the FC kept at the level you report, then I wouldn't worry. It doesn't take much chlorine to kill microorganisms in a short time, but it takes a considerable concentration to produce rashes.

Also, kids tend to open their eyes under water more than adults and that could provide some irritation after a long swim. But I think the relatively high salt level of a pool equiped with a SWG is actually more comforting to the eyes.

Greg

Thanks Greg. Yes its an outdoor pool and I do have a FAS/DPD test kit. I just measured FC today and it was 4.5ppm and CC was 0.

They do a lot of swimming and its getting hotter. I was just wondering if maybe they are extra sensitive to chlorine. Maybe I should reduce the % output on the SWG and increase pump time from 8rhs to 12hrs per day? and maybe aim for 3.5ppm FC?

There is one more thing. The yard is not fully grassed yet as its a new home and every time there is a lot of wind soil ends up in the pool. Once a week I vacuum this dirt out. when I brush it I can see the dirt. Most of it ends up going down the main drain. then I vacuum the rest up.

[polyvue]

Thanks Greg. Yes its an outdoor pool and I do have a FAS/DPD test kit. I just measured FC today and it was 4.5ppm and CC was 0.

They do a lot of swimming and its getting hotter. I was just wondering if maybe they are extra sensitive to chlorine. Maybe I should reduce the % output on the SWG and increase pump time from 8rhs to 12hrs per day? and maybe aim for 3.5ppm FC?

There is one more thing. The yard is not fully grassed yet as its a new home and every time there is a lot of wind soil ends up in the pool. Once a week I vacuum this dirt out. when I brush it I can see the dirt. Most of it ends up going down the main drain. then I vacuum the rest up.

With no measurable CCs your current regimen seems to work fine but if you can consistently keep 3.5 or more FC in the water that should still provide sufficient oxidation/sanitation. Depends a little on bather load so if you have kids swimming all day long try to err on the high side.

Keep an eye on your filter pressure. The dirt may clog the filter a bit sooner than if the surrounding area was landscaped. Pools are always happier with additional filtration so if it's needed (say, the water is not perfectly clear at the end of 8 hrs of pumping or you're getting significant accumulations of dirt on the floor or swim-outs), why not? Of course, you'll see a comparable increase in energy usage/cost.

I'm pretty conservative about running my pump/filter longer than necessary because my pool pump is a single speed energy hog, oversized for the plumbing and pushes enough water to effect 1 turnover in less than 3 hours.

[Gavin]

Thanks Greg. Yes its an outdoor pool and I do have a FAS/DPD test kit. I just measured FC today and it was 4.5ppm and CC was 0.

They do a lot of swimming and its getting hotter. I was just wondering if maybe they are extra sensitive to chlorine. Maybe I should reduce the % output on the SWG and increase pump time from 8rhs to 12hrs per day? and maybe aim for 3.5ppm FC?

There is one more thing. The yard is not fully grassed yet as its a new home and every time there is a lot of wind soil ends up in the pool. Once a week I vacuum this dirt out. when I brush it I can see the dirt. Most of it ends up going down the main drain. then I vacuum the rest up.

With no measurable CCs your current regimen seems to work fine but if you can consistently keep 3.5 or more FC in the water that should still provide sufficient oxidation/sanitation. Depends a little on bather load so if you have kids swimming all day long try to err on the high side.

Keep an eye on your filter pressure. The dirt may clog the filter a bit sooner than if the surrounding area was landscaped. Pools are always happier with additional filtration so if it's needed (say, the water is not perfectly clear at the end of 8 hrs of pumping or you're getting significant accumulations of dirt on the floor or swim-outs), why not? Of course, you'll see a comparable increase in energy usage/cost.

I'm pretty conservative about running my pump/filter longer than necessary because my pool pump is a single speed energy hog, oversized for the plumbing and pushes enough water to effect 1 turnover in less than 3 hours.

Thanks. I think I will aim for FC of 4ppm and run the pump twice a day for 6hrs each. But backwashing sounds like an idea. seems a lot a dirt gets in the pool. I should clean the cell and backwash. I've turned % back down to 70% and will increase pump time. Thanks.