Copy this code into your page. Free to use with the credit link.
advertisement
The order matters
The sequence — clean before filling, circulate before testing, balance before shocking — exists because each step makes the next one honest. Testing stagnant water gives false readings; chlorinating before removing debris wastes chlorine on leaves. An opening that follows the order costs less in chemicals than one that jumps straight to dumping in shock.
The first water test is the whole opening
Winter changes water: rain and snowmelt dilute CYA and salt, cold water holds different pH, and covers leak organics. The first test after 24 hours of circulation tells you everything you actually need to buy — which is why the shopping list above stays minimal until you know. Test first, buy second, dose third.
Salt pools: don't trust the cell yet
Salt water generators need warm water (usually 60°F+) and correct salinity to work; many read low or refuse to run at opening temperatures. Establish chlorine with liquid chlorine first, verify salt with the salt calculator after circulation, and let the cell take over once the water warms.
Frequently asked questions
When should I open my pool?
When daytime temperatures start holding above ~70°F — before the water warms enough for algae to get a head start. Opening early to clear water is far cheaper than opening late to a green pool.
What chemicals do I need to open my pool?
At minimum: liquid chlorine to establish sanitizer, a test kit that reads free chlorine, pH, alkalinity, and CYA, plus whatever the first test says you're missing (commonly stabilizer after a winter of rain/snow dilution, and acid or baking soda for balance).
Should I shock the pool when opening it?
If the water is clear, a normal chlorine dose to target is usually enough. Cloudy or green water needs the full reach-and-hold treatment — see our green pool calculator for the exact plan.
How long after opening can we swim?
Once the water is clear, free chlorine is at target (not above), and pH is 7.2–7.8 — often the same day for a clean opening, a week or more if it opened green.