Why can't you use household bleach to shock the pool since it has the same active ingredient as the stuff at the pool place sodium hyptaclorite?
Because bleach is only 5% sodium hyptochlorite, while the chlorine you buy at the pool store is about 96%.
well household bleach is 3 to 6% sodium hypochlorite, The pool stuff is 10.5 to 13% sodium hypochlorite so you would need to use much more. When shocking you need to raise your current chlorine level up by 10 times any less and you are wasting chemical and your time, Just don't use the cented kind it will create to many phosphates and cost even more in the long run.
Compare the entire label of each container. Minor change or addition to 1st answer. the 96% chlor is going to be granular and the percentage is more like 98%. It will also have conditioner in it. To compare apples to apples the liquid pool store chlor is 12.5% as opposed to 5%. Now, which do you think is going to do a better job? Household bleach has 95 % inert ingredients in it among other things that you probably do not want in your pool.
5% = more trips to the store, larger quantities or volumn used to accomplish job. Comes in throwaway bottles and cardboard containers that may leak in transit and that have to be rinsed and/or sent to the dump or recycled. Hard to pour - they glug, glug, glug. Takes longer to work. Probably not at the required 5% when finally sold to you because it sat on the dock at the back of the store for hours in the sunlight in clear bottles. Degrades fast.
12.5% = Pay a deposit but it can be refunded. Comes in a protective plastic bin or case that can contain a leak should one occur. Bottles are refillable and pour directly to the pool WITHOUT THE GLUG, GLUG, GLUG. Easy to pour. Less time to work. Degrades slower.
You CAN use liquid chlorine bleach to shock the pool. It is generally 5.25% sodium hypochlorite whereas the pool store liquid chlorine is about 10 to 12% sodium hypochlorite. You'll just need to use roughly twice as much. To get 5 ppm rise in a 20,000 gallon pool, you will need about 1 gallon of liquid chlorine from the pool store and that would be like 2 gallons of liquid chlorine bleach from the grocery. Liquid bleach at the store generally comes in opaque white plastic bottles that prevent light from passing through. Don't use scented bleach as it will just contaminate your pool with fragrances which include a variety of chemicals that you just don't need. Read the label. Best to buy one that is unscented and has the % sodium hypchlorite listed. I just bought 10 gallons of cheap store brand stuff that is unscented and states on the label that it is 5.25% sodium hypochlorite. I saved 50% of my money this way, but I do have more jugs to handle. I consider it worth it.
SAFETY FIRST!!! Whether using pool store liquid chlorine or grocery store bleach or any other chemicals, always remember safety first in handling any chemicals.--Use proper protective gear, handle carefully, don't mix chemicals, be serious and not playful, take care not to splash. Follow label directions or material safety data sheets. Never mix chlorine and non-chlorine bleach or other chemicals. Poisonous gas may result.