In times of economic recession, many homeowners are looking for alternative means for services that were previously paid. Another victim of the dwindling economy--the local pool boy. You can do your own pool work, including using chlorine--even without a filter.
Can you put chlorine in a pool without a filter?
Short answer--yes. The first response, however, would be why would you use a pool without a filter? The sand filter or other filtration system is essential to the health and safety of the swimmers. It is also necessary to have a circulation pump for maximum chlorination. For the answer to this question, though, we'll assume that the pool is store-bought residential with a filtration system in place but the questioner wants to add chlorine at another point in the pool.
The simplest way and most commonly found in pools bought at retailers is to add a basket that simply floats on top of the water and circles the pool. It holds a 2- to 3-inch tablet that dissolves as it circulates. The biggest complaint with these is that the chlorine tablet doesn't dissolve fast enough or penetrate to the bottom of the pool, thus leaving areas that can easily be contaminated by bacteria. Even multiple baskets may not rectify this problem. A possible solution to this would be to anchor the basket with just a small piece of rope near the water inlet jet coming from the filter/circulation pump. This ensures the tablet will dissolve quicker, but if there is only one jet it once again can limit the range of the chlorine. It is also not recommended to just drop a tablet into the pool and let it sink to the bottom and dissolve on it's own. This can damage the liner and is completely ineffective. Also, do not pour bleach into the pool. Bleach is chlorine, but the bleach you buy in a jug is not strong enough to effectively chlorinate a pool. It's just a waste of time and money.
The best method is to install an inline chlorinator to a water inlet jet. It's best to do this with a pool that has two or more inlet jets. Tablet chlorinators and liquid drip chlorinators are available but vary by pool size, so make sure you check with a local pool supplier and get the right model. These usually have installation instructions with them or the pool suppliers can install them. Never install a chlorinator before the filter or circulating pump, as it could result in build up of gas within the filter/pump. Even with an inline chlorinator, it is possible to develop "dead areas" in the pool. The pool should be cleaned daily, so while your doing this just take a pool net and run it along the bottom of the pool. This just stirs the water and helps put chlorine where there was none.