Pool Water Console

New here, or just want the why? Start with what you're trying to do, get to know the tools, then meet the six numbers your water is made of — explained the way a good pool tech would over the fence, not a textbook.

What do you want to do?

Pick a goal — we'll drop you on the right tool with everything set up.

What this console can do

Seven tabs, one job each. Nothing leaves your device.

Learn you are here
The goal launcher above, this tour of the tools, and the chemistry below. Come back any time you hit a word you don't know.
Dose
The heart of it. Enter readings — by hand, by slider, or by scanning a test strip from a photo — then pick what you're doing: Get it right (balance to target, in the right order), SLAM the algae (shock level & hold), or Monitor & log (just record and watch the trend). Each gives an exact, checkable plan you can print or copy.
Buy
A season's supplies scaled to your pool's size, with the smartest month to buy each — and the one rule that chlorine is the only thing you never stockpile.
Care
The cleaning rhythm that keeps algae from getting a foothold, plus calculators for fill volume, pump runtime, and electricity cost.
Plan
This week's outlook (add your ZIP for a live forecast) and the step-by-step playbooks for opening, closing, and chasing a leak.
Trends
A logbook that turns your readings into a picture — every number plotted against its safe band, with events like shocks and algae marked so you can see cause and effect.
Fix-it
A symptom solver for when something's off, and the full mustard-algae playbook — the one that trips most people up.

Why you test — the 60-second version

The big picture

Your pool is a tiny ocean, and you're its lifeguard.

Ten thousand gallons sitting in the sun is a perfect home for algae and bacteria. One thing keeps it swimmable: a sanitizer — chlorine — patrolling the water. Testing is just asking the water two questions: is the guard still on duty, and is anything getting in its way?

Everything else you measure is about keeping that guard strong, efficient, and gentle — strong enough to win, efficient so you don't waste money, gentle so it doesn't sting your eyes or eat your liner. Test, and you dose once. Guess, and you chase the same problem all week.

Safety

A measured sanitizer level is the difference between clean water and a swim in someone's bathwater. You can't see bacteria — you test for it.

Money

The right dose, once, beats three panic-buys of chlorine and a bag of shock. Most "expensive" pools are just untested ones.

Protection

Balanced water protects the liner, pump seals, and ladder. Off-balance water quietly corrodes or scales the gear you paid for.

Meet the six numbers

Each one is a character with a job. Learn the cast and a test strip stops being a mystery. The grey line under each is exactly how your strip or kit might label it.

Free Chlorine FC
The bodyguard on duty. "Free" means unused — chlorine that's standing ready to destroy the next germ or algae spore. This is the number; if it falls to zero, the pool is unguarded and the clock to green starts ticking. Read it most often — every day or two in summer. Too low and you're exposed; too high and it's harsh on skin and eyes. On your kit: Free Chlorine · FC · Free Available Chlorine · Free Cl
Total & Combined Chlorine TC / CC
The bodyguard's tired, spent shifts. Total Chlorine is everyone on the clock; subtract Free and the gap is Combined chlorine — guards that already fought and are now worn out (chemists call these chloramines). That gap is the real source of the stinging eyes and the strong "pool smell" people blame on too much chlorine. It's actually a sign of not enough fresh chlorine. A gap over ~0.5 ppm is the classic "time to shock" signal. On your kit: Total Chlorine · TC · Total Cl  → Combined = TC − FC
pH acid ↔ base
The water's mood — and it decides how hard your chlorine hits. On a 0–14 scale, 7 is neutral. Drift low (acidic) and water stings eyes and slowly corrodes metal; drift high and it clouds, leaves chalky scale, and makes chlorine lazy — at pH 8.0 your sanitizer works at a fraction of its power. Aim for 7.6, right around the pH of a human tear, which is why it feels comfortable. On your kit: pH — labeled the same on every test in the world.
Total Alkalinity TA
pH's shock absorber. Alkalinity is a buffer — a reserve that soaks up acids and bases so pH doesn't lurch every time it rains or you add a chemical. Too low and pH bounces around uncontrollably; too high and pH gets stubborn and slowly climbs. That's why a pro sets alkalinity first, then fine-tunes pH on top of a steady foundation. On your kit: Total Alkalinity · Alkalinity · TA · Alk · Buffer
Cyanuric Acid CYA · stabilizer
Sunscreen for your chlorine. Bare chlorine in summer sun is gone in a couple of hours — UV destroys it. CYA wraps each chlorine molecule in a little UV shield so it survives the day. But there's a catch worthy of its own rule: too much CYA over-protects, holding chlorine back so it can't work. So CYA doesn't just protect your chlorine — it sets how much chlorine you need. That single relationship is the most important idea in pool care, and it's the next section. On your kit: Cyanuric Acid · Stabilizer · Conditioner · CYA
Calcium Hardness CH
How "hungry" the water is for minerals. Soft water (low calcium) tries to dissolve minerals out of whatever it touches — it'll etch plaster and corrode metal. Hard water (high calcium) drops them back out as cloudiness and scale. How much it matters depends on your surface: on a vinyl liner there's nothing for soft water to eat (low-priority — don't chase it), fiberglass wants a moderate level to protect the gelcoat, and plaster/gunite genuinely needs it — set your surface in Pool setup and the target follows. On your kit: Calcium Hardness · Total Hardness · Hardness · CH

The one idea a pro leads with

If you remember one thing from this whole tab, make it this. It's the model used by chemists and the most respected pool-care community alike.

Your chlorine target is a percentage of your CYA — not a fixed number
Here's the trap a "keep chlorine at 1–3 ppm" chart sets: at high CYA, 3 ppm is uselessly weak and algae walks right in; at zero CYA, 3 ppm is overkill that burns off by noon. Because CYA both shields and restrains chlorine, the only honest target scales with it:
target FC  ≈  7.5% of CYA
never below ≈  5% of CYA  ← the algae line
shock level ≈  40% of CYA

So at CYA 40 you keep FC near 3, never let it dip under 2, and shock at 16. Raise CYA to 80 and every one of those numbers doubles. This app does that arithmetic for you on the Dose tab — but now you know why the target moves. "Shock" isn't a special product, by the way: it just means raising FC to that 40% line with liquid chlorine or cal-hypo, then letting it fall back on its own.

The order — and the rule that prevents every mishap

Fix things bottom-up, like building a house
1. Alkalinity — pour the foundation so pH stays put. 2. pH — set it on that steady base. 3. Calcium — rarely needed on vinyl, essential on plaster. 4. CYA — slow to dissolve; set it and wait a week. 5. Chlorine — last, because the four above decide how well it works. Skip the order and you'll re-do steps you already paid for.
The one safety rule under all of it
Never mix chemicals, and always add chemical to water — never the reverse. Acid and chlorine together make poison gas; water poured into acid can erupt. One product at a time, poured low and slow into the pool with the pump running, dosed in the evening. The full four-rule version lives on the Dose tab under "How to add it — safely." A guess can be re-tested; a bad pour can't always be undone.
Ready? Head to the Dose tab and enter even one reading — or tap Test & balance at the top of this page. Not sure of a term mid-test? Every reading row has an that explains it.

Pool setup
edit

Rough guides (48″ wall): 15 ft round ≈ 5,000 · 18 ft ≈ 7,500 · 21 ft ≈ 10,000 · 24 ft ≈ 13,000 gal.

Sets your calcium target — vinyl barely needs it, plaster genuinely does.

How do you chlorinate day-to-day? The thing that keeps chlorine in the water between tests — doses, reminders, and the Buy tab all follow it.

What matters most to you? Tunes where you aim inside the safe band and what gets recommended — never the safety lines themselves.

Everything here is remembered on this device.

Your test readings

Tap a number to type it, or slide. Colors and badges show your range live — tap a row’s if a strip name is unfamiliar.

No doses yetEnter your readings above and tap Show my dose list.
My strip says "OK" but this app disagrees — who's right?

Usually both are. They disagree for two honest reasons, and knowing them makes the disagreement stop being annoying:

1. The bottle's range is generic; this console's is yours. The strip bottle prints one "OK" band for every pool on earth — e.g. free chlorine 1–3. But the right chlorine level depends on your stabilizer: at CYA 70, an FC of 2 is genuinely unprotected even though the bottle colors it "OK," and at CYA 0 an FC of 3 is more than you need. Same with alkalinity: many bottles print 80–120, while this console aims 70–90 because that's where pH behaves best with trichlor or liquid chlorine. When the ranges differ, trust the computed one — it knows your CYA, your chlorine type, and your surface; the bottle doesn't.

2. Strips read in coarse color blocks. Your pad only has colors for 0 · 0.5 · 1 · 3 · 5 · 10 — a real FC of 2.2 has no block of its own, so two people can honestly read the same pad as "1" or "3." This console already accounts for that: any reading within one test-step of a band edge (about ±0.5 FC, ±0.1 pH, ±10 TA/CYA, ±25 CH) is treated as in range — "within test tolerance" — and no dose is asked for, because your test couldn't verify a correction that small anyway.

So in practice: if this console says "within test tolerance," relax — you're fine, don't chase the number. If it asks for a dose while your bottle says "OK," the bottle is being generic, not wrong — the dose list explains exactly why in each step's Why. And before any big decision a strip triggered (like draining for high CYA), confirm with a drop-count test kit — strips are for watching, drops are for deciding.

Know your numbers

Your target numbers

Where you're aiming — at a glance, no reading required.

The one rule that saves the most money
Your chlorine target isn't a number. It's a percentage of your stabilizer.

Cyanuric acid (CYA) shields chlorine from sunlight — but also dampens how hard it works. So the right chlorine level scales with CYA. Drag to watch the safe band move.

min0
target0
shock0
0 ppm free chlorine— ppm
40 ppm

Pro tools

Two calculators the pros lean on. Tap to open — they use your readings and pool setup automatically.

What happens if I add… — preview a dose before you pour

The dose list in reverse — check an amount before you pour it, or see what that scoop you already added did. Uses your pool volume.

Water balance (CSI) — etching or scaling?

The chemist's single number: does your water want to dissolve calcium (etch plaster, corrode) or drop it (scale)? Computed from your pH, alkalinity, calcium, stabilizer, and water temperature above. Between −0.3 and +0.3 is happy water.

Closing tip: set the temp to your coldest winter water (~40°F) before you winterize — cold water drives CSI down, and water that's balanced in August can spend the winter quietly etching plaster. Balance for the winter number, not the summer one.

Borates — the optional 30–50 ppm upgrade

The pro's finishing touch. Borates at 30–50 ppm act as a second pH buffer that specifically resists the upward drift trichlor-free pools fight all summer, mildly suppress algae, and give the water that soft, sparkly "resort" feel. Like CYA, they only leave by dilution — set them once, then top up only after big water changes. You'll need borate test strips (LaMotte) to measure them.

Notes: never exceed ~50 ppm. Borates are mildly toxic to pets in quantity — a dog that habitually drinks from the pool is the one real reason to skip them. They don't change your chlorine or CSI targets.

How to add it — safely

The four rules that prevent every chemical mishap, then how to add each one.

Four rules, every time

  • Never mix chemicals — not in a bucket, not in the skimmer. Acid + chlorine makes toxic gas. One product at a time, minutes apart.
  • Always add chemical to water, never water to chemical — and acid into water, never the reverse. Pour low and slow with the pump running.
  • Evening is best. Dose at dusk, run the pump ~1 hour to mix, then cover. Less sun loss, better mixing.
  • Gear up & store smart. Goggles and gloves for acid and powders. Store acid and chlorine apart, sealed, cool, dry, off the ground, away from kids and pets. Never reuse a scoop between products.
3″ trichlor tablets (pucks) — the feeder chemical
Stabilized trichlor, ~90% available chlorine, 8 oz a tablet. Per 10,000 gal, one puck delivers roughly +5 ppm FC as it dissolves — and about +3 ppm CYA that never leaves. Turn on “Trichlor pucks in a feeder” in Pool setup and this app will size your weekly load and set a refill reminder. Keep an inline feeder's dial low (~2 of 8 is a common starting point; a floater half-open). Here's the catch: pucks add about 3 ppm CYA for every 5 ppm of chlorine, so when they carry the full load through a hot month CYA can climb 30–50+ ppm — fast. Watch CYA monthly: as it nears ~60–70, dial the feeder back, cover demand with liquid or cal-hypo, and plan a partial drain-and-refill — diluting is the only thing that lowers CYA. Load pucks only in a feeder or floater — never the skimmer of a pool whose pump ever stops (acidic water sits in the throat), and never loose on a vinyl liner. For a fast bump or to shock, use liquid/cal-hypo (pucks are too slow). Puck labels often ask for TA 100–120; this app aims 70–90, which also works — if pH keeps sliding down from the pucks, let TA ride toward ~90–100 for more buffer.
Liquid chlorine
Your tool for a fast FC bump or to lift FC without adding CYA. Pour slowly in front of a return jet with the pump running; walk it around the perimeter. Don't splash the liner or cover.
Muriatic acid
Pump on, pour low and slow into the deepest spot, then brush/circulate. (To lower alkalinity instead: pour in one spot with the pump off, then aerate.) Acid into water.
Cal-hypo shock (65%)
Your superchlorinator, usually in pre-measured 1-lb bags. One bag raises FC about +8 ppm per 10,000 gal — so to hit shock level (~16 at CYA 40) figure about 2 bags per 10k gal. A common rhythm: superchlorinate weekly when water is above 80°F, every other week below. Cal-hypo adds a little calcium (fine on vinyl, watch it on plaster if CH is already high) and zero CYA. Pre-dissolve in a bucket (granules into water, stir) and pour in front of a return — undissolved granules will bleach a permanent spot on a liner. Never let cal-hypo and trichlor pucks touch — don't mix them or share a scoop; combined, even as dust, the two can react and catch fire. Store them apart.
Baking soda / soda ash
Broadcast in wide arcs across the surface with the pump running. Soda ash may cloud the water briefly — it clears.
Stabilizer (cyanuric acid)
Mostly an opening job — and if you run pucks, they keep adding CYA all season so you'll rarely need extra. On liquid or a salt cell, set it once at opening and it only leaves by dilution. To add it: sock it in the skimmer basket and run the pump. Don't clean the filter for 24–48h. Never pour raw granules on a liner.
Polyquat algaecide (e.g. No Mor Problems)
Preventative, not a rescue. Add it directly to the pool (never mixed with chlorine). Season start: 6 oz per 10,000 gal. Upkeep: about 3 oz per pound of shock or per 2 pucks you add (roughly weekly in peak heat). Don't swim until FC is back under ~3 ppm. For an actual bloom, shock and brush — algaecide alone won't clear it. Skip copper-based algaecides: they stain.

The thinking behind it

Optional. Your dose list already has everything you need to act.

The chlorine ÷ stabilizer rule

Free chlorine sanitizes. CYA is sunscreen for it — without CYA, summer sun burns off most of your FC in hours. But CYA also binds chlorine, so a fixed "1–3 ppm" rule misleads. The fix is a ratio:

target FC ≈ 7.5% of CYA
never below ≈ 5% of CYA ← algae line
shock level ≈ 40% of CYA

At CYA 40: keep FC near 3, never under 2, shock at 16. Dose to target the moment FC dips. That one habit prevents almost every green pool.

Why the order matters (and wait times)

1. Alkalinity first — buffers pH. ~20 min. 2. pH — re-test after TA settles, bring to ~7.6. Acid ~30 min, soda ash ~20 min. 3. Calcium — rarely needed on vinyl, essential on plaster. 4. Stabilizer — slow; sock it in the skimmer, retest in a week. 5. Chlorine last; swim under ~5 ppm.

Tablets, liquid & the CYA tradeoff

Your trichlor tablets are convenient and self-feeding, but they quietly add CYA that never leaves (~3 ppm CYA for every ~5 ppm of chlorine a tablet gives). A whole summer of tablets can push CYA past 80–100 — and once it's high, your FC target rises with it and the only way back down is to drain and refill. The fix isn't to quit tablets; it's to track CYA and, when it climbs into the 60s, dial the feeder back and cover the gap with liquid (zero CYA) or cal-hypo shock. ("Shock" just means raising FC to ~40% of your CYA — using liquid or cal-hypo, not tablets.)

A season's worth of supplies for May–September, scaled to your pool — with the smartest time to buy each. The one rule: chlorine is the only thing you don't stockpile.

A cover that's on when the pool is idle cuts chlorine use noticeably — it changes the estimate.

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Season chemical estimate.

Your season shopping list

Chlorine price check — is that jug a deal?

Chlorine products can't be compared by sticker price — a cheap weak jug loses to a pricier strong one. Enter what's on the shelf and get the number that actually matters: dollars per +1 ppm of chlorine in your pool.

When to buy for the best price

Apr — pre-season
Fresh test reagents and your first chlorine. Reagents fade after ~a year — start the season with new ones.
May–Sep — in season
Only liquid chlorine and reagents need to be fresh. If you keep a jug of liquid for fast bumps, buy it small and check the date stamp — it dies in weeks. Your trichlor and cal-hypo don't need this.
Sep–Oct — closeout
Stock up on the keepers: the trichlor bucket, cal-hypo bags, No Mor Problems, muriatic acid, baking soda, a little stabilizer. Clearance prices, and they last for years. Best time for covers, a spare cartridge, and gear too.
Why shelf life decides the timing

Liquid chlorine (sodium hypochlorite) loses strength fast — roughly half its punch over a few months at room temperature, faster in heat and light. Buying a season's worth in spring means pouring weak, expensive water by August. Buy it fresh, in small amounts, store it cool and dark.

Test reagents are the other short-lived item — about a year, less once opened. Refresh them each spring so your numbers stay trustworthy.

Everything else keeps for years sealed and dry: muriatic acid, baking soda, soda ash, stabilizer, cal-hypo, and most algaecides. These are exactly what to grab on end-of-season clearance. (Keep calcium chloride and granulars sealed — they pull moisture from the air.)

Your gear — lifespan & value

A typical above-ground setup — pump, cartridge filter, solar cover — with rough lifespans and replacement costs so nothing surprises the budget. Adjust to your own gear; replacement reminders live on the Care tab.

The cheapest "repair" is prevention. Clearing baskets so the pump never runs starved, draining the pump and filter fully before winter, and keeping the cover out of high chlorine add years to each of these.

About the estimates. Chlorine cost follows the day-to-day method in Pool setup (puck feeder, liquid by hand, or salt cell) with cal-hypo for shocking, scaled to your volume and cover habit. Real use swings with sun, heat, and swimmers. Dollar figures are rough mid-range prices and vary by store and year — a budget sketch, not a quote.

Cleaning is half of clear water; sanitizing is the other half. Keep this rhythm and algae rarely gets a foothold.

The 15-minute weekly loop

Skim → empty both baskets → brush the shady corners → quick test → top up chlorine. That's the whole routine most weeks. Rinse the cartridge only when pressure says so; deep-clean monthly. Don't over-do it.

Cleaning rhythm

Daily
Skim floating debris, bugs, and pollen. Glance under the cover when you pull it.
2–3× / wk
Test chlorine and pH; top up to target. Empty the skimmer basket — a full one starves the pump.
Weekly
Brush walls and floor — especially shaded, low-flow corners and behind the ladder. Vacuum, and clear the pump strainer basket (your pre-filter).
When PSI says
Pull and hose off the cartridge when the gauge climbs ~8–10 psi over its clean reading. Note your clean pressure once (say it's 14 psi) and clean around 22–24 psi — not on a fixed day.
Monthly
Deep-clean the cartridge — soak it in filter cleaner (or diluted muriatic for scale) to clear oils and buildup a hose won't. Check the pump lid o-ring and re-lube it with Jack's 327.
Open / close
May: open, balance, set stabilizer. September: balance, raise FC a touch, winterize. (Full steps on the Plan tab.)
The pump basket is your pre-filter. Check it weekly and clear it when it's ~½ full (more after a storm). A clogged basket makes the pump work harder, move less water, and burn through chlorine. The skimmer basket is the first line — empty it more often.
Vinyl liner: use a nylon brush, never stainless — steel bristles scratch the liner. For heavy debris, vacuum to waste rather than through the filter.
Spring tree pollen: keep the cover on through the heaviest tree-pollen weeks and run the filter longer — pollen feeds algae and drains chlorine.

How long to run the pump

Goal: turn the whole pool over 1–2× a day, mostly in daylight. Your Hayward SwimPro LX is 70 GPM (1.5 HP) — already filled in.

Run it during the day. Chlorine burns off and algae grows when the sun's up, so that's when circulation matters most. After any chemical dose, run at least 1 hour to mix. During an algae fight, run 24/7.
Cooler months (May open, September): you can trim to ~6 hours — cold water needs less. On a time-of-use electric rate, shift hours to off-peak, but keep enough daytime running to distribute chlorine.

What the pump costs to run

Your Hayward is a single-speed motor — full power whenever it's on. Here's the monthly bite, and how it stacks up against everything you spend on chemicals.

How long to fill or top off

After winter or a dry spell, find out how long the hose needs to run. For the best number, measure your hose with the 1-gallon test.

1-gallon test0.0s
Tap Start as the hose hits a 1-gal jug, Stop when it's full — I'll set your GPM.
Set a phone timer before you start. A hose left running can flood the yard, wash out under the liner, and run up a water or well bill fast. Don't leave it unattended for long, fill over the wall (never into the skimmer), and stop a touch early. A big fill dilutes your chemistry — when you're done, retest: chlorine, stabilizer, and hardness will read lower.

Using the cover well

A solar cover is a cleanliness and chlorine-saving tool — but only if the water stays sanitized underneath.

  • It keeps the junk out. Leaves, pollen, dust, and bugs stay off the water — less skimming, lighter filter load, less organic matter eating chlorine.
  • It makes chlorine last. Blocking sunlight slows UV burn-off, so FC holds longer between top-ups — real savings over a season.
  • The trap: warm water under a cover with low chlorine is an algae incubator. Never cover a pool whose FC has dropped below target — sanitize first, then cover.
  • Dose, mix, then cover. Add chlorine in the evening, run the pump ~1 hour, then cover. Sealing it right after dosing traps gas that bleaches and shortens the cover's life.
  • Let it breathe. Pull the cover back during swims and a few times a week so the water off-gasses — and so you can spot trouble early.
  • Clean the cover itself. Rinse debris off the top before removing it. If the underside turns slimy, scrub with a diluted bleach solution and rinse. Store it off the water, out of strong sun and high chlorine, so it lasts.

Tonight's heat & evaporation

What one night actually costs you, cover off vs on. Evaporation is the sneaky one — it takes both water and heat (every gallon that evaporates drags ~8,800 BTU with it). Physics-based estimate, not a promise.

Clear nights lose more — the pool radiates to a cold sky.

Where your water temp is heading

Wildlife & your pool

To everything that hops, buzzes, or waddles, a pool reads as a pond — and steep walls make it a trap. Ten minutes of humane setup keeps visitors alive, and your water cleaner for it.

  • Give everything a way out. An escape ramp (a FrogLog or Critter Skimr, or just a rough board or towel clipped over the edge into the water) turns the pool from a death trap into a detour. Above-ground walls are sheer — fit at least one ramp, two on a big pool. Frogs, toads, mice, chipmunks, even waterlogged bees use them.
  • Check the skimmer first, every warm morning. It's where overnight swimmers end up — usually alive. Lift the basket gently and release amphibians into damp shade; a rinse with plain water helps a chlorine-soaked frog recover.
  • Bees at the waterline aren't hunting you — they're hauling water home, and they recruit nest-mates to a reliable source. Set a bee bar 20+ feet away (shallow dish, pebbles to stand on, topped up daily) and they re-route within days. Don't swat at the water's edge — that's where stings happen. And never spray a swarm: it's docile, temporary, and a local beekeeper will usually collect it free.
  • Ducks & geese: never feed them. Feeding turns a stopover into residency, and droppings into a sanitizer problem. Keep the cover on when idle, use a motion sprinkler for repeat visitors, and be patient — most move on in days. Ducklings can't climb out: ramp in, herd gently toward it, and let mom do the rest. Legal note: migratory waterfowl and their nests are federally protected — gentle hazing is fine, anything more needs permits.
  • Covers cut both ways. A taut cover keeps animals out of the water; a loose one traps them beneath it or drowns them in the rain puddle on top. Glance under and over the cover each time you pull it.
  • Your pool is nobody's water bowl. Chlorinated water is rough on small wildlife and pets. A plain water station in the shade — refreshed daily like the bee bar — gives everyone a better option than your top step.
Something didn't make it? See Fix-it · Animal in the pool for safe removal — and the one case (raccoon droppings) where chlorine alone doesn't clear the water.

Maintenance minders

Tap Done when you do each one — this device remembers the date and tells you when it's due again.

What to expect this week in your area, and the playbooks for opening, closing, and chasing a leak. Weekly guidance uses temperate-climate averages, and can pull a live forecast for your ZIP.

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This week

Enter your ZIP for a free 7-day forecast — no account, saved only on this device.

Special-time playbooks

Spring opening (May)
  1. Clear & remove the winter cover
    Pump off standing water and sweep debris first so none dumps into the pool. Clean, dry, and store the winter cover; remove the air pillow.
  2. Reconnect equipment
    Reinstall drain plugs in the pump and filter, lubricate o-rings, reconnect hoses and the skimmer. If the cartridge is worn or 2–3 seasons old, replace it now.
  3. Top up & run
    Fill to mid-skimmer, prime the pump, and run the filter 24 hours straight to mix and clear.
  4. Balance in order
    Test, then set alkalinity → pH → stabilizer (to ~40) → chlorine. Use the Dose tab for exact amounts. Brush and vacuum any settled debris.
  5. Clear it, then cover
    If the water's cloudy or tinted, shock to SLAM level (Fix-it tab) until it passes the overnight test. Once balanced and clear, put the solar cover back on.
Winterizing (≈ October)

Wait until the water is below ~60°F (algae goes dormant) — usually October here. Closing while it's still warm invites a bloom under the cover.

  1. Balance & sanitize
    Set pH ~7.2–7.6, alkalinity 80–100, and bring FC up to a healthy level so it carries through the cold months. Add a winter algaecide.
  2. Clean it out
    Brush, vacuum, empty baskets. Rinse and clean the cartridge one last time.
  3. Lower the water
    Drain a few inches below the skimmer and return (or fit a skimmer plug / freeze-guard). This keeps ice off the fittings.
  4. Drain ALL equipment — the big one
    Freeze damage is the #1 winter killer. Pull the drain plugs from the pump and filter, drain the hoses completely, and store the pump, filter, and hoses indoors if you can. Water left in them cracks the housing.
  5. Cover for winter
    Float a centered air pillow (it absorbs ice expansion), put on a solid or mesh winter cover, and secure it with the cable/winch or cover seal. Store the solar cover, ladder, and gear.
If you think there's a leak
  1. Rule out evaporation — the bucket test
    Set a bucket of pool water on a step so its inside water matches the pool level; mark both. After 24–48h, if the pool dropped more than the bucket, it's a real leak. (Normal summer evaporation is ~¼ inch a day — far less under your cover.)
  2. Find the level it stops at
    Let the water drop on its own. If it stalls at a certain height, the leak is at that level — often a return fitting, the skimmer throat, or a liner spot you can now inspect.
  3. Check fittings first (most leaks)
    With the pump running, look for drips at the pump union, filter, hose clamps, skimmer, and returns — and for wet ground or a soggy pad outside the pool. Most leaks are here and fix with a tightened clamp or a new gasket/o-ring.
  4. Dye-test a suspected liner hole
    Pump off, water still. Squeeze a little dye (or food coloring) near the suspect spot — if it gets sucked into a hole, you've found it. Patch small vinyl tears with an underwater patch kit.
  5. Protect the equipment & know when to call
    If it's losing water fast, turn the pump off so it doesn't run dry and pull air. A liner seam, a buried plumbing line, or unexplained loss is worth a leak-detection pro.

Weather note. Weekly guidance is based on temperate-climate (northern US) normals built into this page. Enter your ZIP and tap "Get forecast" to pull a free live 7-day outlook (no account needed) and tailor the advice; if you're offline or it's blocked, the averages still apply. Your ZIP stays on this device and is sent to the lookup services only to find your area.

Your pool over time. Log a reading and the trends light up — every number is plotted against its safe band, so drift is obvious at a glance.

Why bother logging?

One reading tells you about today. A handful tells you about your pool.

A single test is a snapshot — fine for dosing right now. But pools fail on trends, not snapshots: chlorine that's quietly sliding a little lower each day, CYA creeping up all summer from tablets, pH that always drifts back high. None of that shows up in one reading. It jumps out the moment you have a line.

Log even a few and this tab starts earning its keep — it catches the slide before the water goes green, shows whether a fix actually held, and turns "I think it's been off lately" into a picture you can act on. The events you tag (a shock, a fresh fill, first algae) drop onto the same timeline, so cause and effect line up.

See drift early

A downward FC line two weeks before a bloom is your free warning. Dose to the trend, not the panic.

Prove a fix worked

Tagged a shock or a CYA dilution? Watch the next readings to confirm it actually moved — or didn't.

Learn your pool

Every pool has habits. After a season you'll know yours — how fast it eats chlorine, when CYA climbs.

Log a reading

Quick entry below, or tap Log to history on the Dose tab. Dates default to today — set When to backdate.

Note an issue or event

Tag what happened — algae, cloudy water, a shock, a filter clean. They land on the trend chart so you can see cause and effect.

At a glance

Trend chart

History

Backup & transfer

Your history lives in this browser only. Export to back it up or move it to another device; import to bring it back.

Something off? Start with the symptom picker, or jump to the mustard-algae playbook — the one that trips people up most.

Mustard algae

stubborn

Yellow-to-tan dusty patches, usually on shaded walls and floor. It brushes away easily but comes right back — because it's chlorine-resistant and reinfects from anything that touched the water (toys, brush, pole, swimsuits, the cover). Killing it takes a higher chlorine hold and decontaminating your gear. Skip the gear and it returns every time.

  1. Balance for the fight
    Test CYA (it sets the shock level) and lower pH toward 7.2 so chlorine works at full strength.
  2. Brush everything hard
    Knock it off every surface — walls, floor, steps, and especially shaded corners and behind the ladder. Brushing exposes the cells to chlorine.
  3. Raise chlorine to shock level — and hold it
    Bring FC up to shock level (≈40% of your CYA) and keep it there. Test and re-dose back up 2–4× a day; mustard takes longer than green algae to clear.
  4. Decontaminate the gear
    The step people skip — and why it comes back. During the high-chlorine hold, sanitize everything that touched the water:

    Decon checklist

    Toss items into the pool during the hold, or bleach-soak / hot-wash them. Tap each as you go.

    • Run, brush, clean the filter
      Pump runs 24/7. Brush daily. Hose off the cartridge as it loads up with dead algae — a clogged cartridge stalls the cleanup.
    • Confirm it's dead, then ease off
      Hold shock level until it passes all three checks below, then let FC drift back to your normal target. Keep FC at the high end for two weeks to stop a rebound.
      You're done when all three are true: water is clear, no visible algae after brushing, and you lose 1 ppm or less of FC overnight (test at dusk and again at dawn before sun hits).
    Algaecide? Your No Mor Problems is a preventative — it helps stop algae from starting, but it won't clear an active mustard bloom. What actually clears mustard is holding shock level + brushing + decontaminating gear. Avoid cheap "metal" algaecides — they can stain a vinyl pool.

    Common issues solver

    Pick what you're seeing.

    Shocking safely

    • Never mix chemicals — add one at a time, minutes apart. Acid + chlorine makes toxic gas.
    • Pre-dissolve granular shock in a bucket (into water, stir) so it never sits on the vinyl liner.
    • Don't swim while FC is at shock level — wait until it drops under ~5 ppm.
    • Gloves and goggles, and dose at dusk with the pump running.
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