How do you lower the chlorine level?

Answer

NEVER, NEVER, NEVER USE SODIUM THIOSULFATE IN CHLORINATED WATER TO DECHLORINATE IT. THIS HAS BEEN TAKEN OFF THE MARKET AND IS OUTLAWED IN MOST STATES! EPA REGULATIONS BAN IT'S USE IN LABORATORIES. IT IS A CARCINOGENIC!!!!!!!!!!!

It had been used in certified laboratories for years and years until the late 1990's when it was found to be a carcinogenic. Just getting it on your skin on a daily basis was found to be a cancer causing danger. It is adsorbed through the skin. It is now considered hazardous waste and must be handled as such.

I have also seen this product in pool stores, in pool test kits and am amazed to see it there. To start with it is not stable for over 24 hours in a liquid form and must be kept refrigerated and in a dark container to last for even a week. But it sits on the shelves in stores to be sold for sometimes over a year? I as a lab supervisor have titrated this solution repeatedly for years using EPA Standard Methods to verify how many drops of it would be necessary to dechlorinate a 100ml sample. Until it was taken out of the labs as a carcinogenic.

NC Water Pollution Grade IV Certified Operator

I question the above ANSWER from "NC Water Pollution"

I'M NOT SURE YOUR ANSWER IS VALID BASED ON THE FOLLOWING INFORMATION I FOUND...

I did some research on your very scary recommendation NOT to use SODIUM THIOSULFATE to reduce the chlorine level in swimming pools. It seems that SODIUM THIOSULFATE is not a CARCINOGEN!!! See item #11 (Toxicological Information) in the following link from MSDS.

http://www.jtbaker.com/msds/englishhtml/S5230.htm

It appears that it is a relatively harmless chemical. Can you explain your findings?

Signed, Worried Pool Owner.

Answer

Why is swimming in chemicals such an excepted practice? Chlorine, Salt Generated Chlorine, Shock, Stabilizers, where does it stop? You add one chemical you need to add two more to balance the pool. Technology has moved well beyond chemical addition! Look into UV systems...not Ozone generated by UV, straight UV technology will Kill algae, not just put it to sleep like chlorine does. UV also destroys more bacteria..which is why you use chemicals - than any other system including and especially salt systems. Read the World Health Organization - Healthy Pool Guidelines. Read what the Centers For Disease Control and the scientific community says about swimming pools and your health. Read about cryptosporidium in your pool and your kids. Read about THM's and HAA's. Read about reproductive and developmental problems associated with Chlorine Disinfection By Products (DBP's). Then you will quit using shock, salt, stabilizers, acids,yellow treat, green treat, and use a light bulb instead. Technology is a beautiful thing.

Answer

Add Sodium thiosulfate. Also known as chlorine neutraliser.

Answer

Even a PHD chemist cannot keep a body of water at optimal chemical balance indefinitely. The "best" (though not least inexpensive) way to lower free chlorine level is to replace the water with potable water which is usually about 3-4 ppm free chlorine. We can't yet mimic nature perfectly. The more pertinent question may be as follows...Why am I having to adjust my free chlorine level so often? To answer such question...Total alkalinity outside the optimal range can have an extreme adverse effect on chlorine stabilization. High water temperature or direct sunlight can also adversely effect free chlorine. Injected chlorine gas is more volatile (less stable) than chlorine tablets such as dichlor or trichlor. Biologicals & carbon compounds such as body fluids, oils, soaps, beverages, etc can wreak havoc on water balance chemistry including chlorine levels. Water balance chemistry calculations include ph, total alkalinity, calcium hardness, sanitizer level, and saturation index and are all interrelated (relative).

Answer

Practical solutions:

1. Wait for a couple of days and let the chlorine level return to normal on its own. Be sure to take your solar blanket off as sunlight will help break down the chlorine (especially if you used non-stabilized shock).

2. Use a chlorine reducing agent. They are usually called "After Shock" or something similar. These chemicals are available at your local pool supply store and are usually based on some formulation of sodium thiosulfate.

Answer

Ultraviolet technology can reduce Chlorine use by over 80%. UV has grown in municipal water treatment and it is great for swimming pools. UV will destroy more bacteria, virus, algae and germs than chlorine and do it MUCH faster.

First answer by ID0000000000. Last edit by Mford50532. Contributor trust: 0 [recommend contributor]. Question popularity: 214 [recommend question]