Intex pool chemicals: start-up doses by model
An Intex pool needs chlorine, a test kit, and small amounts of stabilizer and baking soda.
Always follow your product’s label directions. Pool and spa chlorine, bromine, shock and algaecides are EPA-registered pesticides: use products labeled for pool or spa use, and don’t swim or soak until levels are within the limit on your product’s label. If this page and a label disagree, the label wins.
On this page (9 sections)
For a Prism Frame 12 ft × 30 in (1,718 gallons), 11 fl oz of 6% household bleach takes fresh fill water from 0 to 3 ppm free chlorine. The table below gives start-up amounts for other models.
What you need (short list)
- A test kit or strips that read free chlorine (FC), pH, total alkalinity (TA), and stabilizer (CYA). See how to read test strips if you're new to them.
- Chlorine. For pools under about 5,000 gallons, plain unscented household bleach (6% or 8.25%) or pool liquid chlorine (10% or 12.5%) is the easiest to dose in small, exact amounts. Stabilized tablets (trichlor) work in a floater but add stabilizer every week, which builds up in a pool that is rarely drained.
- Stabilizer (cyanuric acid, CYA) for an outdoor pool, so sunlight doesn't destroy your chlorine within hours. Aim for 30–50 ppm.
- Baking soda to raise alkalinity, and a pH reducer (muriatic acid or dry acid) for when pH rises.
- Optional: a skimmer net and a spare filter cartridge, so one can dry while the other runs.
You don't need clarifiers, algaecides, or "start-up kits" to get clean water. Chlorine at the right level for your stabilizer and a working filter do most of the job. The general version of this list for any pool is in pool chemicals for beginners.
Pick your model: capacity and start-up doses
These amounts assume fresh tap water with no chlorine and no stabilizer. Capacities are Intex's rated numbers. The full list of 25 models is on the Intex pool sizes page.
| Model (rated capacity) | Chlorine: FC 0 → 3 ppm, 6% bleach | Stabilizer: CYA 0 → 30 ppm | Baking soda: TA +20 ppm (only if TA is low) |
|---|---|---|---|
| Easy Set 10 ft × 30 in (1,018 gal) | 6.3 fl oz | 4.1 oz | 4.6 oz |
| Easy Set 12 ft × 30 in (1,485 gal) | 9.2 fl oz | 5.9 oz | 6.7 oz |
| Metal Frame / Prism Frame 12 ft × 30 in (1,718 gal) | 11 fl oz | 6.9 oz | 7.7 oz |
| Easy Set 15 ft × 33 in (2,587 gal) | 16 fl oz | 10.4 oz | 11.6 oz |
| Prism Frame 15 ft × 48 in (4,440 gal) | 27 fl oz | 1.1 lb | 1.25 lb |
| Easy Set 18 ft × 48 in (5,455 gal) | 34 fl oz | 1.35 lb | 1.55 lb |
| Greywood Prism Frame 18 ft × 48 in (6,423 gal) | 40 fl oz | 1.6 lb | 1.8 lb |
| Ultra XTR Frame 18 ft × 52 in (6,981 gal) | 43 fl oz | 1.75 lb | 1.95 lb |
| Ultra XTR Frame 24 ft × 52 in (12,481 gal) | 77 fl oz | 3.1 lb | 3.5 lb |
Bleach percent is by weight, as on the label. With 10% pool liquid chlorine, use about 62% of the bleach amount (for example, 6.6 fl oz instead of 11 fl oz for 1,718 gallons). Stabilizer amounts are for 100% cyanuric acid granules. Always follow the product label.
First fill, step by step
- Fill and start the pump. Fill to the level in your manual and run the filter pump. If you fill from a well, test for iron and copper first: metals can stain the liner once chlorine goes in.
- Test. Write down FC, pH, TA, and CYA. Tap water is usually FC 0–1 and CYA 0.
- Alkalinity first. If TA is under 80 ppm, add baking soda, spreading it over the surface with the pump running. Wait 30 minutes.
- pH next. If pH is above 7.6, add acid in a small first dose. The maintenance guide explains why small pools overshoot easily.
- Stabilizer. Granules dissolve slowly. A common approach is to dissolve them in a bucket of warm water, or hang them in a mesh bag in front of the return jet, rather than letting them sit on the liner. Retest CYA after 3–7 days, not the same day.
- Chlorine last. Pour it slowly in front of the return jet. Your minimum depends on CYA: about 2.5 ppm at CYA 30 and 3 ppm at CYA 40.
- Retest the next day and top up chlorine. On a new pool with fresh water, the first few days tell you how fast your pool uses chlorine.
Weekly routine
The CDC's advice for home pools is to test chlorine and pH at least twice a day, more often with many swimmers. Small Intex pools lose chlorine quickly on hot, sunny days, so test before each swim if you can't test twice a day. Enter your numbers here to get an ordered list of doses for your gallons:
- Chlorine: top up to your target every day or two. An 8 ft or 10 ft pool may need only a few teaspoons of bleach a day.
- pH: keep 7.4–7.6. Bleach and liquid chlorine push pH up slightly. Trichlor tablets pull it down.
- Filter: rinse the cartridge when flow at the return weakens, and replace it when rinsing no longer helps. Run the pump every day, longer in hot weather and while you treat a problem.
- Stabilizer: test monthly. It doesn't get used up. It only goes down when water is replaced.
Green Intex pool
Green water means algae grew faster than your chlorine could kill it. The fix is the same as for any pool: use a product labeled for shocking pools, and take the amount and the timing from its label. Most labels list a dose per 10,000 gallons, so work out your pool's share first. A Prism Frame 15 ft × 48 in holds 4,440 gallons, which is 0.444 of 10,000. If the label says 1 lb per 10,000 gallons, add about 7.1 oz (0.444 × 16 oz). Brush the walls and floor, clean the cartridge every day while you treat, and keep testing. If the water hasn't cleared after a few days of following the label, repeat as the label directs or ask a pool professional. Step-by-step instructions are in how to clear a green pool.
Don't swim until free chlorine is back at or below the swim limit printed on the label, which is often 4 ppm.
Salt water system models
Some Ultra XTR sets come with Intex's Krystal Clear saltwater system, which makes chlorine from dissolved salt. Intex's owner's manual (as published on manual-hosting sites; we could not open a copy on intexcorp.com) gives an ideal salt range of 2,500–3,500 ppm, with 3,000 ppm as optimal. It asks for non-iodized salt that is at least 99.8% pure. From fresh water to 3,000 ppm, that is about:
- Rectangular Ultra XTR 24 × 12 ft × 52 in (8,403 gal): 210 lb, six 40 lb bags;
- Ultra XTR Frame 24 ft × 52 in (12,481 gal): 312 lb, eight 40 lb bags;
- Rectangular Ultra XTR 32 × 16 ft × 52 in (14,364 gal): 360 lb, nine 40 lb bags.
Add salt in steps, and retest after 24 hours of circulation. You can always add more, but lowering salt means draining. You still need to test free chlorine and pH, because the system only makes chlorine. It doesn't measure it.
Taking it down for winter
Intex's support guide asks you to bring the pump and accessories indoors before temperatures fall below 32 °F (0 °C), and to store a drained pool completely dry at temperatures between about 34 °F and 104 °F (+1 to +40 °C). Several guides say Intex manuals recommend taking the pool down when temperatures reach 41 °F (5 °C). We could not confirm that on an Intex page, so check your own manual. If you leave the pool up, balance the water, add a cover and an air pillow, and plug the wall fittings. Full steps are in how to close an above-ground pool.
Safety
Never mix chlorine and acid, or two chlorine products, even in a dry bucket. Add chemicals to water, never water to chemicals, one product at a time with the pump running. Wear gloves and eye protection, and store chlorine and acid apart, out of reach of children. For poisoning questions, call Poison Control at 1-800-222-1222. Always follow the product label. It is a violation of federal law to use a pesticide product in a manner inconsistent with its labeling.
FAQ
What chemicals do I put in my Intex pool?
Chlorine (bleach or liquid chlorine is easiest for small pools), stabilizer (CYA) to 30–50 ppm, baking soda if alkalinity is below 80 ppm, and a pH reducer if pH is above 7.6. Amounts depend on your model's capacity. Use the table above, or see small-pool doses in teaspoons for the smallest sizes.
Should the Intex filter pump run while I add chemicals?
Yes. Add one product at a time with the pump running, pour it slowly in front of the return jet, and wait about 30 minutes between products. Run the pump every day, longer in hot weather and while you treat a problem.
How often should I clean an Intex filter cartridge?
Rinse it when the flow at the return weakens, and replace it when rinsing no longer helps. While you clear green water, clean it every day. A spare cartridge lets one dry while the other runs.
Sources
- CDC, Home pool and hot tub water treatment and testing: cdc.gov
- Intex Support, Getting the pool ready for winter: intexsupport.com
- Intex Krystal Clear Saltwater System owner's manual (third-party copy): manuals.plus
- Intex product pages (capacities), read 2026-09-29: intexcorp.com
- CDC, pool chemical injuries: archive.cdc.gov