The first question every new stock tank pool owner asks is "what do I put in the water." The second question, usually about a week later, is "do I actually need to keep putting it in." Both questions have honest answers, and there are two real paths most Aussie owners settle into for stock tank pool water care. One uses chlorine, sparingly, the way you'd dose a small chemical-care job. The other uses hydrogen peroxide, the way a small but growing share of US and Australian owners run their pools chlorine-free. This is the plain comparison of both.
We'll cover what each method actually does, what it costs in real Australian dollars, what it asks of you week to week, and where each one falls down. Then a short call on which one suits which household. None of this is gatekept. You can buy everything mentioned in this guide at Bunnings or order it online before lunch.
What "water care" actually means in a stock tank pool
A stock tank pool is the same chemistry as any other pool. The water needs three things to stay clear: a sanitiser that kills bacteria and algae, a balanced pH so the sanitiser actually works and your skin stays comfortable, and a filtration cycle that pulls the rest out. The pump and filter that ships with every Terra Tanks Family Plunge and Urban Plunge handles the filtration. The sanitiser and pH are on you.
What's different about a stock tank pool is the volume. A Family Plunge holds about 2,650 litres. An Urban Plunge holds about 1,476 litres. A full backyard concrete pool holds 25,000 to 60,000. The dose maths is an order of magnitude smaller. Most people overdose without realising, because they're scaling their thinking from a "normal" pool. The smallest possible amount of chemistry, applied consistently, is the right answer in both methods below.
For more on how the pool itself works, sizes, and what comes in the box, the full Australian Stock Tank Pool Guide covers the product side. This piece is purely about the water inside it.
Path 1: The minimum chlorine method
This is the path most Terra Tanks owners run on. It's cheap, it's predictable, and it uses chlorine the way you'd use coffee: enough to do the job, never more.
What you need:
- A pack of Hy-Clor 600g Li'l Pools Chemical Tablets from Bunnings. Around $30.90 per pack. Each pack holds 15 or more 20 g tablets in our field count.
- A floating chlorine dispenser with a closed mode. Around $10 to $20.
- A pool test kit or test strips. Around $15 to $30.
That is the entire shopping list. Three items, under $70 to set up, available in any major Bunnings on a Saturday morning.
The protocol:
One tablet at a time. The dispenser sits closed when you're not topping up, opened a notch when chlorine is being released. Drop in one tablet, set the dispenser to a slow release, and let it dissolve over roughly two weeks. When it's gone, drop in the next one. That's the entire weekly routine.
For a year-round family using the pool every weekend, that works out to about 26 tablets a year, or 1.7 packs. Total chlorine spend, before pH adjusters, is around $54 a year. For summer-only use over five months, expect about 11 tablets, one pack, roughly $25 to $30 a season.
Add a small bottle of pH increaser and a small bottle of pH decreaser. You'll use a teaspoon at a time, twice a season at most. Budget another $20 a year for the two combined.
Why one tablet at a time, never multiple:
Two reasons, both important to galvanised steel. First, multiple tablets in a small body of water spikes the chlorine concentration well past what the water needs and what the steel was designed to sit in. Second, broken tablet pieces that fall through the dispenser and settle on the floor of the pool create a high-chlorine micro-zone that can pit and rust the steel faster than the dissolved chlorine in the bulk water ever would. The Gypsy Pools team in the US, who pioneered most of the public guidance on stock tank water care, has been blunt about this for years: never let tablet fragments settle. Always use a dispenser. Always one tablet at a time.
What it costs you in time:
Five minutes a week. Test the water, top up the dispenser if needed, adjust pH on the rare day it's drifted. That's the full routine.
Path 2: The hydrogen peroxide method (Gypsy Pools approach)
The H2O2 method swaps chlorine for a 35% food-grade hydrogen peroxide. The water has no chlorine smell, the chemistry is gentler on skin, hair, and swimwear, and it's safe enough that drained pool water can be poured directly onto a lawn or garden. The method was popularised by Gypsy Pools, and most of the Australian owners we know who use it learned it through their guidance.
What you need:
- 35% food-grade hydrogen peroxide, sold in 5 or 25 litre containers by Australian chemical suppliers. Pricing varies by supplier and quantity, with bulk drums working out cheaper per litre. Multiple brands available online.
- Hydrogen peroxide test strips that read in parts per million.
- A dosing jug. Glass or food-safe plastic only.
The protocol:
Maintain hydrogen peroxide levels between 50 and 70 ppm. Test weekly with strips, more often in heatwaves. Top up by adding a measured dose to the pool when levels drop. The pool needs sunlight on it through the day, because UV from the sun is what activates the peroxide's sanitising action. The Bureau of Meteorology's UV index forecast is a quick check of how much UV your area is getting on any given day. Heat also accelerates the breakdown, so you'll use more in summer than in shoulder seasons.
Cost reality:
The standard Australian supplier protocol (Chemox publishes this on their 5L pool-grade label) is 500 mL of 35% food-grade H2O2 per 10,000 litres per week, halved in winter. For a Family Plunge at 2,650 litres that's roughly 130 mL a week in the warm months and 65 mL a week in winter. Year-round, that's about 5 to 8 litres of consumable peroxide a year, depending on how sunny and hot your summer runs.
A 5-litre container of 35% food-grade H2O2 from an Australian supplier like Chemox sits around $130 in 2026. Test strips add roughly $30 a year. So a realistic annual spend for a year-round H2O2 setup lands in the $130 to $200 a year range. The higher-end Gypsy Pools maintenance target (50 to 70 ppm) can push dosing up in hot, sunny conditions, so a heavy-summer year could land closer to $250 to $300. We'll firm these numbers up once a Terra Tanks owner completes a full year on H2O2 and lets us cite their spend.
One regulatory note:
Hydrogen peroxide as a primary pool sanitiser is not currently APVMA-tested in Australia for pool use, so the H2O2 path sits outside the formal regulatory framework. Many Aussie owners run it happily; we mention it because you should know.
Where this method doesn't work:
If your pool sits in shade for most of the day, hydrogen peroxide won't activate properly and you'll be paying for sanitiser that isn't doing its job. The Gypsy Pools guidance is the same on this point: shaded tanks should run chlorine, not peroxide. If your install is under a pergola, a dense tree canopy, or on the south side of the house, run Path 1.
The honest comparison
Here's how the two paths stack up on the questions buyers actually ask.
Cost per year, year-round family use:
- Chlorine: around $54, plus $20 for pH adjusters. About $75 a year.
- Hydrogen peroxide: roughly $130 to $200 a year at current Australian bulk supplier pricing and the standard 500 mL per 10,000 L weekly protocol. A heavier dosing pattern (Gypsy Pools 50 to 70 ppm target in a hot summer) can push closer to $250 to $300. Full breakdown in the Path 2 section above.
Time per week:
- Chlorine: 5 minutes.
- Hydrogen peroxide: 5 to 10 minutes, with more attentive testing in summer.
Smell and feel of the water:
- Chlorine: faint chlorine smell at the dispensed dose. Skin can dry out after long soaks for sensitive users.
- Hydrogen peroxide: no smell. Water feels softer. No chlorine residue on swimwear.
Safety around plants and pets:
- Chlorine: drained pool water needs to dilute before being poured onto a garden bed.
- Hydrogen peroxide: drained pool water is essentially safe for gardens, lawns, and animals.
Suits a tank in full shade:
- Chlorine: yes.
- Hydrogen peroxide: no.
Suits an owner who doesn't want to think about it:
- Chlorine: yes, the protocol is closer to set and forget.
- Hydrogen peroxide: requires slightly more attention.
What about the steel itself
A common worry: doesn't chlorine eat galvanised steel?
The honest answer is that dissolved chlorine in the bulk water of a stock tank pool, at the small dose this protocol uses, does not meaningfully degrade the steel within the life of the pool. The damage that does happen comes from concentrated chlorine sitting in direct contact with the steel: broken tablet fragments on the floor, a dispenser left in one corner of the pool with high-chlorine output, or repeated shock-dosing of the pool to clear an algae bloom. Avoid all three and the steel is fine.
A pool liner takes the steel out of the equation entirely. The chlorine sits in the water against the liner, not the steel. If you want a fully chlorine-tolerant setup with no compromises, the Premium Vinyl Pool Liner at $675 is the off-switch on water-care anxiety.
The water-care mistakes both methods make
A few patterns repeat in customer photos, regardless of which sanitiser they're using.
Overdosing. Treating a 2,650 L stock tank pool like a 30,000 L backyard pool. The dose maths is roughly an order of magnitude smaller. When in doubt, start with less.
Skipping the test kit. "Looks clear" is not the same as "is balanced." A $20 test kit pays for itself in one avoided algae bloom.
Letting tablets fragment. Always use a dispenser. Never throw tablets directly into the pool. Always one tablet at a time.
Ignoring pH. Sanitiser efficacy collapses outside a pH range of roughly 7.2 to 7.6. Test pH first, sanitise second.
Forgetting the filter. A daily pump and filter cycle is what makes any chemistry work. Run it for a few hours each day in summer, less in cooler months. Without circulation the water goes cloudy in days.
A simple weekly water-care rhythm
For either path, the routine looks like this.
Weekly, about 5 minutes:
- Test sanitiser level and pH.
- Top up dispenser or dose H2O2 as needed.
- Skim leaves, empty pump basket.
Monthly:
- Backwash or rinse the filter cartridge.
- Wipe the waterline with a soft cloth if scum is building up.
Twice a season:
- Adjust pH with the appropriate booster or reducer if your weekly test shows drift.
Annually:
- Drain and refill the pool. Roughly $5 to $15 at metro water rates for a Family Plunge.
That is the whole job. Five minutes a week, half an hour a month, half a day once a year.
Which one is right for your household
If you're a year-round family with kids, a tank in part to full sun, and you want the cheapest possible protocol that just works, run the chlorine method with the Hy-Clor closed-dispenser routine. This is the path most Terra Tanks owners use.
If you're a household with sensitive skin, an interest in chemical-free living, a tank in full sun, and you don't mind a slightly higher annual spend, run the hydrogen peroxide method via the Gypsy Pools approach.
If you want zero water-care anxiety regardless of method, add the Premium Vinyl Pool Liner and stop worrying about the steel.
And if you want help fitting the pool into the wider backyard (surfaces, planting, privacy), the stock tank pool landscaping guide covers the yard around the water.
Ready to keep it simple
If you don't have a pool yet, the Family Plunge and Urban Plunge ship with everything you need for either water-care path, except the consumables: pool, pump, filter, UV cover, plumbing, and the engineering certificate.
If you've already got the pool and you're staring at the chemicals aisle in Bunnings: grab a pack of Hy-Clor 600g tablets, a $10 floating dispenser, and a basic test kit. That's the full kit for the chlorine path. Drop in one tablet, set the dispenser to slow release, and you're done for two weeks.
The pool is the easy part. The water care is genuinely easier than you've been led to believe.