Domakihub The Right Order to Add Pool Chemicals
Why sequencing alkalinity, pH, calcium, and chlorine correctly saves money and keeps your pool clear.
Reviewed by Domakihub pool pros · 2026-06-23 · 5 min read
Adding pool chemicals in the wrong order is one of the most common — and costly — mistakes pool owners make. The video above walks through the correct sequence visually; this article gives you the exact steps with the reasoning behind each one, tailored to the longer swim seasons and harder tap water you find across Greece. Whether you manage a private villa, a holiday rental, or a hotel pool, getting this right from the start means fewer repeat treatments and cleaner water all season.
Why Sequence Is Not Optional
Pool chemistry is a system of interdependencies. Each parameter — total alkalinity, pH, calcium hardness, and chlorine — directly affects how well the others work. Add chlorine before you balance pH, and a significant portion of it becomes inactive before it ever touches the water. Add calcium hardness while pH is still drifting, and you risk cloudy water or scale deposits on your tiles and heat exchanger.
Greek pools face additional pressure: summer temperatures routinely exceed 30 °C, UV intensity is high, and many municipal water supplies carry elevated calcium to begin with. These conditions make an already fragile chemistry balance more volatile, which means following the correct addition order is not just good practice — it is what separates a pool that stays clear from one you are constantly firefighting.
The Foundation Principle: Always Balance Before You Sanitise
The governing rule behind the entire sequence is that chlorine can only sanitise effectively within a specific pH window (7.2–7.6). Outside that range, free chlorine — the active form — drops sharply. So the first three steps are about creating the conditions in which chlorine will actually work. Skipping ahead to sanitisation before those conditions exist means you are burning through an expensive product for little result.
This is especially relevant if you are reopening a pool at the start of the Greek season in April or May, or correcting a cloudy pool mid-August when a holiday rental handover is hours away. In both scenarios, the instinct is to dump chlorine and hope. The correct move is always to test first, balance in order, then sanitise.
The Correct Order to Add Pool Chemicals
- 1
Step 1 — Adjust Total Alkalinity First
Total alkalinity (TA) acts as a pH buffer. Target range is 80–120 ppm. If TA is too low, pH will swing wildly each time anyone swims or it rains; if it is too high, pH becomes almost impossible to bring down. Use sodium bicarbonate to raise TA or muriatic acid to lower it. Add the chemical to the deep end with the pump running, then wait at least 6 hours — ideally a full circulation cycle — before testing again. Do not move to the next step until TA is stable in range.
- 2
Step 2 — Balance pH
Once alkalinity is locked in, pH adjustments become predictable and hold. Target pH is 7.2–7.6 — lower end is better for chlorine efficiency, higher end is gentler on eyes and surfaces. Use pH increaser (soda ash) or pH decreaser (muriatic acid or sodium bisulfate) in small doses, broadcasting across the pool surface with the pump running. Retest after 4–6 hours. Because you already stabilised alkalinity in Step 1, pH should settle and stay put rather than drifting back overnight.
- 3
Step 3 — Raise Calcium Hardness If Needed
Calcium hardness (CH) should sit between 200–400 ppm. Too low, and water becomes corrosive — it will pull calcium from plaster walls, grout, and fittings, causing permanent surface damage. Too high, and you get scale and cloudy water. In many parts of Greece, incoming tap water is already hard, so you may not need to add calcium at all — but you do need to test for it. If CH is below 200 ppm, add calcium chloride slowly, pre-dissolved in a bucket of pool water, and add it around the pool perimeter. Never add calcium and pH adjusters at the same time.
- 4
Step 4 — Add Chlorine to Sanitise
With alkalinity, pH, and calcium all in range, chlorine can now work at full efficiency. For routine maintenance, add chlorine tablets to a floating dispenser or skimmer basket to maintain 1–3 ppm of free chlorine. For a shock treatment — after a party, heavy rain, or visible algae — broadcast granular shock (calcium hypochlorite or dichloroisocyanurate) across the pool in the evening to avoid UV degradation. Always add shock to water, never water to shock. Wait until free chlorine drops back below 5 ppm before anyone swims.
- 5
Step 5 — Add Algaecide and Other Supplements Last
Algaecide, clarifier, phosphate remover, and enzyme products all go in last, after chlorine levels have normalised. Adding algaecide while chlorine is very high wastes the product — high chlorine will break it down before it can do its job. Clarifiers and enzymes also work best in balanced, properly chlorinated water. For pools in Greece that are used continuously from May through October, a weekly maintenance dose of algaecide is a practical insurance policy, given the warm water temperatures that algae thrive in.
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FAQ
- How long should I wait between adding each chemical?
- Wait at least one full pump circulation cycle between each step — typically 4 to 6 hours with the pump running. This ensures the chemical is fully distributed and the water reading you test reflects the actual pool balance, not just the area around where you added the product. Rushing this step is the most common reason people over-dose and then have to correct in the opposite direction.
- Can I add multiple chemicals on the same day if I have to fix a pool quickly?
- Yes, but still maintain the correct order and give the pump time to circulate between each addition. Do not add two chemicals at the same time or in rapid succession. The exception is never to mix chemicals — even the same chemical in different forms — either in the bucket or in the water within a short window. Holiday rental handovers create real pressure to fix a pool fast, but adding everything at once typically makes the problem worse and delays clarity further.
- Do I need to follow this order for a saltwater pool too?
- Yes. A salt chlorine generator produces chlorine from salt electrolysis, but it does not balance alkalinity, pH, or calcium hardness — those still need to be managed manually in the same sequence. In fact, pH tends to creep upward in saltwater pools as chlorine is generated, so testing and adjusting pH after locking in alkalinity is especially important. The generator will not compensate for out-of-range chemistry; it simply produces chlorine into whatever water conditions exist.