For those with a salt chlorinator, if you are having problems the most common things to check are (a) that the cell is clean and working, (b) it has water flow, (c) you have salt in your pool, (d) it is running long enough and (e) it has stabiliser.
If the salt chlorinator cell is dirty the unit will not be able to produce as much chlorine. To clean the cell simply soak it in a weak acid solution (1 part acid, 10 part water) or a cell cleaner while the calcium dissolves. If the chlorinator gauge is showing low you may need salt. Otherwise your cell may have worn. Cells last between 3 and 10 years depending on quality and maintenance.
If your unit is showing low on it’s indicator even with the correct amount of salt then you need a replacement cell.
Do not brush or scrape the plates of your cell to remove calcium as this will shorten its life expectancy.
Most salt chlorinators produce between 15 – 30 grams of chlorine per hour at peak. This means that they must run for 8-12 hours daily in summer to produce the equivalent of one cup of chlorine.
Make sure you have a stabiliser (isocyanuric acid) level of 50-100 in your pool. Due to the slow production rate of chlorinators on a hot day the sun can remove chlorine faster than your cell can make it. Stabiliser holds the chlorine in the water. Without stabiliser your pool may not get enough chlorine and can get algae.
For those with liquid chlorinators, they are much simpler. Most importantly, where the chlorine tube goes into the pool pipes there is a plastic injector. Unscrew it and pull the clear tube out. This tube will clog occasionally with crystals from the liquid chlorine. If it is blocked your pool will not be getting chlorine. If the pump is working but the chlorine drum is not being used, check the squeeze tube in the pump and the clear tube from the drum to the pump for holes. If the pump is not working or runs irregularly you may have a problem with the gearbox or motor. If these all seem fine then make sure your filter is running properly and you have chlorine in the supply container.