Both will kill bacteria if you add them to water however there are lots of bacteria adapted to live in salt water but I don't know of many adapted to live with chlorine.
Chlorine is more electronegative than iodine.
No it means that your water balance is incorrect. Get the water tested at the pool shop unless you know how to do it yourself and you will need to make chemical adjustments.
Chlorine
It depends on your 'danger' level. Any amount of chlorine can be dangerous. It only takes a few drops in a gallon of water to disinfect it (kill every living thing in there) after only a few minutes. Chlorine is classified as a toxin, yet it is put in our drinking water and in pools and used in spas. For a normal sized spa, I would never pour more than a cup of chlorine into the spa. 10 ppm is considered the max. If your spa is green and you are not going to use it then feel free to pour 2 or more cups in it. You're better off draining it at this point. To prevent chlorine breakdown, it is recommended that you add stabilizer and its level will depend on how big your spa is. Chlorine is dangerous because it can damage liners and upset water balance. I suggest that you use 2 ppm of chlorine or more then shock your water for it will prevent the bad odor.
Yes Chlorine is poisonous and can be extremely iritating especialy to the more sensetive parts of the body.
Bacteria (usually) can be killed with ordinary soap or diluted cholrine bleach.
Chlorine, as well as other sanitizers for water, kill bacteria and algae in the pool water to keep it more safe for bathers.
You can add little chlorine to the water to make it bacteriostatic. You can find the chlorine in the water for months together, keeping it bacteria free. The pure water can not be stored for long and can be contaminated with bacteria, any time. The risk of chlorinated water being carcinogenic is theoretical, rather than practical. When you drink the water, most of the chlorine is eaten up by food in the stomach and by the mucous lining of the stomach. The advantages of chlorine in water are far more than the disadvantages. Because the chlorine is very economical, there is no godfather for the same.
Chlorine as a gas is poisonous but when dissolved in water it kills harmful bacteria. The gas then slowly dissipates into the atmosphere and is gone in a couple of hours. Many more people have been saved from severe illnesses like cholera and typhoid transmitted by water borne bacteria than have been adversely affected by the addition of Chlorine. Better disinfecting of water supplies and sewerage in the future will be achieved usindg ozone gas.
Neither are bacteria.
more chlorine = less seed germination
Both the sun and bacteria in the pool breaks down the chlorine. You need to keep up the chlorine level daily to keep the pool clear, either by adding or using tablets in the skimmer as you filter. Ues a test kit to check it.
Many things, most notably the removal of chlorine, sediment and bacteria you can read more about here
thus raw or impure water is subjected to the purification process by which the suspended particles, colour, odour and bacteria are removed.water is more important than food.deprivation of water brings death much more quickly than that of food.chlorination is probably the best and the cheapest method of sterilization of water and it is the most effective in destroying pathogenic bacteria.for chlorination, liquid chlorine may be added directly in the municipal water.boiling water for about 15-30 minutes destroys all disease causing bacteria and is one of the reliable method for water sterilization.
more dense
Chlorine is added to water to kill microorganisms such as those that cause cholera and typhoid. However, too much chlorine would be harmful to humans.
No chlorine in Publix Spring Water, but it does contain some other chemicals besides H2O.