1. Shock the hot tub if the chlorine or bromine level is below 2.0 ppm.
2. Check your dial setting.
If using a dispensing device like a salt generator there is a dial that can be turned up. To help find the correct setting that will maintain the desired chlorine or bromine level (typically 1-3 ppm), adjust only one setting per day testing the water after 24 hours to see the effect. Once you find the correct setting do not alter it. When abnormal conditions arise (heavy use or lots of rain) that’s the time to shock the water.
3. Increase the amount of chlorine/bromine being used.
If using a floater, fill it to the top and see if there are any ways to get more water to the chemical. The more chlorine or bromine that is wetted, the greater the output. If spoon feeding chemicals, you may need to increase the amount added or the frequency.
4. Make sure your water is properly balanced.
Water balance is critical to proper sanitization. If the pH is off it makes the chlorine ineffective even if there is enough in the water. Bromine is less affected by changes in pH which is desirable.
5. Look for visible signs of algae.
If algae is about to take a hold of your spa, the chlorine or bromine may be consumed quickly in its effort to prevent the algae. Shock the water or add an algaecide and brush the sides of the spa to prevent this from happening and bring your chlorine/bromine levels back up.
6. Avoid the use of fertilizers near the spa if outdoors and uncovered.
Fertilizers contain nitrates that are food for algae. When they are in the water, chlorine is working very hard to keep the algae at bay so it looks like there is no chlorine present at all. Use an algaecide or shock the pool until your desired chlorine/bromine level is maintained.
7. Consider draining and refilling the spa.
If it has been three months since you last drained and refilled the spa, the water may be to the point where it is difficult to maintain it well. Drain the water, clean the surface and filter cartridges and start again with fresh water.
8. Check the expiration date on your test strips or kit.
Most test strips and testing reagents last only 12 to 18 months. After that date, they may not register readings properly. In addition if you are putting wet hands into the test strip container, you could be contaminating the strips which will shorten their life even further.