Bleach as Disinfectant

• Bleach contains the liquid form of chlorine, sodium hypochlorite. Most standard, solid pool chlorine contains calcium hypochlorite. There's no difference between sodium hypochlorite and calcium hypochlorite other than one's liquid and the other is solid. It only takes about 8 drops of chlorine-containing bleach per gallon of water to disinfect it.
  
  

Bleach Quantities

• To figure out how much bleach to use in a small pool you only need to know how many gallons of water it holds. In a 1,000-gallon pool, you'd need 8,000 drops of bleach to disinfect it (1,000 gallons x 8 drops = 8,000 drops). There are roughly 600 drops per fluid ounce. So you would need about 13.5 fluid ounces of bleach to adequately sanitize a 1,000-gallon pool (8,000/600 = 13.33). Follow the same formula to calculate the volume needed for your pool.
  
  

Disinfectant Levels

• Since chlorine bleach makes for an acceptable substitute for standard pool chlorine, maintaining your pool's health is only a matter of keeping the recommended chlorine disinfectant levels up. The recommended chlorine level in pools is 2 parts per million (ppm), which 8 drops of bleach per gallon achieves. Once chlorine disinfectant levels in a pool are first established, test your pool's chlorine levels regularly and add more bleach as needed.
  
  

Pool pH

• Bleach is highly alkaline, so it will raise pool pH when added. Even small pools must have proper pH in order to maintain chlorine effectiveness. Swimming pool pH levels should be between 7.2 and 7.8, at minimum. The closer pool pH is to between 7.4 and 7.6 the better, though. You can lower pool pH by using muriatic acid (MA). It only takes 1.25 liquid ounces of MA in a 1,000-gallon pool to lower pH back below 7.8 after bleach has been added.
  
  

Chlorine Stabilization

• Chlorine bleach is sensitive to sunlight and it needs to be stabilized if you don't want to have to add it to your small pool on a constant basis. Cyanuric acid (CYA) is the most common chlorine stabilizer used in swimming pools. CYA works to protect pool chlorine from the destabilizing effects of sunlight, and is sometimes known as chlorine conditioner. In a 1,000-gallon pool, about 5.2 ounces of CYA are needed to achieve the recommended levels of 30 to 80 ppm for this product.