Why Intex Pools Are Different
A typical Intex pool holds 1,000–8,000 gallons compared to 15,000+ gallons for an inground pool. That volume difference changes everything about how you manage chemistry.
Any chemical addition has a much bigger impact in a small pool. A half-cup of muriatic acid that barely moves an inground pool's pH by a tenth of a point can drop a small Intex pool's pH dangerously low in the same application. The same dynamic applies to chlorine — a dose that would be appropriate for a 15,000-gallon pool will over-chlorinate a 2,000-gallon Intex to the point of burning eyes and bleaching swimsuits.
The Golden Rule for Intex Pools
Always calculate chemical doses by actual gallons — never by the scoop, cap, or "just eyeball it." Use a pool volume calculator if you don't know your exact gallons. The formula for a round pool: diameter² × depth × 5.9. For rectangular: length × width × depth × 7.5.
The vinyl liner also responds differently than plaster or fiberglass. High cyanuric acid, certain algaecides, and improper shocking can bleach or degrade the liner over time. Getting chemistry right from the start protects your investment and extends the liner's life significantly.
The Intex Filter Problem
Most Intex pools ship with a small cartridge filter. These filters are designed for routine maintenance of clear water — they are not designed to recover a green or cloudy pool. The flow rate and filtration surface area are simply too small to clear problem water in any reasonable timeframe.
Upgrading to a compatible sand filter (such as the Intex Krystal Clear Sand Filter range) makes a significant difference in water clarity maintenance and problem recovery. Sand filters have higher flow rates, backwash to clean themselves, and don't require constant cartridge replacement. If you plan to run your Intex pool for more than one season, the upgrade pays for itself quickly in reduced chemical usage and time spent troubleshooting.
For clearing green water with the stock cartridge filter: run the pump continuously (24/7), rinse or replace the cartridge every 2–4 hours as it loads up with dead algae, and don't expect results in under 48–72 hours. Combine with aggressive shocking and brushing the walls daily.
Weekly Maintenance Routine
Consistency is everything with a small-volume pool. Chemistry shifts fast — what looks fine Monday can be a green swamp by Thursday if you skip a chlorine dose during a heat wave.
Test FC and pH daily in summer
Small volume means fast changes. A hot sunny day, heavy bather load, or missed dose can drop your FC to zero overnight. Daily testing takes two minutes and prevents problem recovery situations that take days.
Add chlorine every 2–3 days in small calculated doses
Dose by gallons, not by feel. Dichlor granules dissolve quickly and work well for regular dosing. Pre-dissolve in a bucket of water before adding to the pool to avoid liner bleaching at the point of contact.
Brush walls and floor weekly
Vinyl liner surfaces attract algae, especially in corners and along the bottom seam where circulation is lowest. Regular brushing disrupts early-stage algae before it takes hold and helps chemicals reach all surfaces.
Vacuum weekly
Debris on the floor — leaves, dirt, sunscreen residue — consumes chlorine rapidly and feeds algae. A manual vacuum or compatible automatic cleaner keeps the floor clean and chlorine demand in check.
Clean or replace the cartridge filter every 1–2 weeks
A clogged cartridge is worse than no filter — it bypasses when fully loaded. Rinse thoroughly with a garden hose, allow to dry if possible, and replace cartridges when they show visible wear or permanent discoloration.
Shock every 1–2 weeks
Use approximately 1 lb of calcium hypochlorite (cal-hypo) per 5,000 gallons. Shock in the evening to prevent UV burn-off. Run the pump overnight. This oxidizes combined chlorine and prevents algae establishment.
Chemicals to Use — and Avoid
The right chemicals for an inground pool are not always the right chemicals for an Intex pool. Small volume and vinyl liner change the calculus significantly.
✅ Use These
- Dichlor granules — dissolve fast, nearly pH neutral, good for regular dosing. Important caveat: dichlor adds CYA with every dose. Watch your CYA level — it will climb over the season and may require a partial drain to reset.
- Liquid chlorine (sodium hypochlorite) — no CYA buildup, ideal for shocking or when CYA is already elevated. Pour slowly around the perimeter with the pump running.
- Calcium hypochlorite (cal-hypo) — powerful for shocking. Pre-dissolve in a bucket before adding. Does raise calcium hardness over time, but Intex pools are typically drained frequently enough that this rarely becomes a problem.
- pH up/down — diluted — use half the recommended dose as a starting point and retest before adding more. Never add full-strength acid directly to a small pool; dilute in a bucket of water first.
🚫 Avoid These
- Trichlor pucks — highly acidic (pH ~3.0) and will continuously drag your pH down in a small pool, requiring constant pH correction. They also raise CYA with every puck that dissolves. A full summer of trichlor in a 2,000-gallon pool can push CYA to 150+ ppm, making chlorine nearly useless.
- Copper-based algaecides — will stain your vinyl liner blue-green, especially if the pH fluctuates. The staining is very difficult to remove. Use polyquat algaecides if you want an algaecide.
- Full-strength pH adjusters added directly — always pre-dilute in a bucket, add slowly with the pump running, and wait 30 minutes before retesting. Easy to dramatically overshoot in small volumes.
Common Intex Problems
🟢 Green Water
Act the same day — small pools go fully green faster than inground pools because the volume-to-algae-load ratio tips quickly. Shock to 10–20 ppm FC, run filter continuously, brush walls and floor daily, and keep FC elevated until the water clears. A sand filter upgrade makes recovery dramatically faster. Check CYA before shocking — if CYA is very high, even elevated FC won't kill the algae.
🫧 Foam on the Surface
Foam is almost always caused by surfactants — cheap algaecides (especially quaternary ammonium types), sunscreen, soap residue from swimsuits washed with detergent, or body oils. Solution: drain 1/3 of the pool and refill with fresh water. If algaecide is the culprit, switch to a polyquat 60 algaecide. Avoid washing swimsuits with detergent; rinse with plain water instead.
🟤 Liner Staining
Brown, rust-colored, or greenish staining is almost always from metals — iron and manganese from well water are the most common culprits. Add a metal sequestrant (chelating agent) before you first add chlorine when filling from a well. If you add chlorine before sequestrant, the metals oxidize and drop out of solution instantly, staining the liner. Sequestrant keeps metals in solution so they can be filtered out gradually.
End-of-Season Storage
Proper storage at the end of the season protects your Intex pool from freeze damage and ensures it's ready to use next year without a full liner replacement.
Drain completely
Do not leave any water in the pool, pump, or filter lines. Water expands when it freezes and will crack fittings, split hoses, and degrade the liner's seams. Even a small amount of trapped water is enough to cause damage over a cold winter.
Dry all components in the sun
Lay the liner flat in direct sunlight for several hours, turning it periodically, until completely dry inside and out. Any moisture trapped in folds will breed mold and mildew during storage, which will be present on the liner surface next spring.
Store filter and pump indoors
The pump motor and filter housing are the most expensive components and the most vulnerable to freeze damage. Store them in a garage, basement, or shed where temperatures stay above freezing.
Inspect and clean the liner before folding
Wipe the entire liner surface with a pool surface cleaner or diluted pool tile cleaner. Check for any algae spots — especially in corners and along bottom seams. Any algae left on the liner will reactivate when the pool is filled next season, giving you an immediate green pool problem on opening day.
Store folded liner in a cool, dry place
Fold loosely and store in the original bag or a large plastic storage bin. Avoid storing in direct sunlight (UV degrades the vinyl) or in a very hot space like an attic in summer. A garage shelf or shed works well.
Not sure how much to add to your Intex pool?
PoolDiag AI calculates exact chemical doses for your actual pool volume. Enter your readings, get your numbers. Free — no sign-up required.
Try PoolDiag Free →Related Guides
- Above Ground Pool Maintenance — expanded guide covering steel-wall and resin frame pools
- Pool Foam: Causes and Fixes — what's causing it and how to clear it without draining
- Why Is My Pool Green? — step-by-step green pool recovery guide
Frequently Asked Questions
How often should I change Intex pool water?
Fully drain and refill every 1–3 years depending on usage. Mid-season partial drains (replacing about 1/3 of the water) help reset chemistry when CYA gets too high — typically above 80 ppm. If you use dichlor granules regularly, CYA can reach problematic levels within a single season.
What chlorine is best for an Intex pool?
Dichlor granules for regular dosing (convenient, dissolves fast, pH neutral), liquid chlorine for shocking or when CYA is already elevated. Avoid trichlor pucks — they're highly acidic and will continuously push pH down in a small volume, requiring constant correction and rapidly elevating CYA.
Can I use a sand filter on an Intex pool?
Yes — many Intex pools are compatible with the Intex Krystal Clear sand filter systems. They provide dramatically better filtration than the stock cartridge filter, self-clean via backwashing, and recover green or cloudy water much faster. If you plan to use your Intex pool for more than one season, it's a worthwhile upgrade.
Why does my Intex pool turn green so fast?
Three factors combine: small volume (any lapse in chlorine affects the entire pool quickly), high UV exposure (no shading, chlorine burns off fast), and undersized filtration (can't clear algae fast enough once it blooms). Test and dose more frequently than you would an inground pool — daily FC checks in summer are not excessive.
How do I winterize an Intex pool?
Drain completely — every last drop from the pool, pump, and filter lines. Dry the liner thoroughly in the sun before folding. Store the pump and filter indoors where temperatures stay above freezing. Do not leave any water in an Intex pool over winter — freeze damage will crack the fittings, split the hoses, and can weaken the liner at the seams, turning a minor storage task into a full replacement.