Coliforms & E. coli
Enter with the supply or through an unsealed lid; shelter in the film. The classic cause of the "stomach bug" that keeps returning to the same household.
Food-grade SS 304 water tanks · 250 – 5000 L
There is a biofilm growing inside your plastic water tank. Your family drinks from it.
Sunlight through the wall, warm water and a plastic surface scratched by every cleaning: within weeks, a slime layer of algae and bacteria is back. AquaVigil tanks are opaque, mirror-finish 304-grade stainless steel. Nothing grows on them, nothing leaches from them, and they are built for a lifetime of use.
- SS 304Food-grade steel
- ISO 90012015 certified
- 250–5000 LVertical & horizontal
- Leak-proofLifelong durability
The problem
What a biofilm is, and why every plastic tank grows one.
A biofilm is a living layer of bacteria bound together in slime, attached to any wet surface it can grip. In a plastic tank, three things feed it: light through the wall, warmth, and a surface that gets rougher every year. Cleaning removes it. It comes back.
Plastic lets light inEven "black" three-layer tanks pass enough light for algae to photosynthesise. Shine a torch inside at night and you'll see the wall glow.
Steel reflects itZero light transmission, and a mirror-polished inner wall with nothing for bacteria to anchor to. The heat bounces off with it.
The slime you feel on the inside wall is not dirt. It is a colony.
Anyone who has cleaned a plastic tank knows the feeling: a slippery film that comes off in sheets, a green tinge, a smell. That film is billions of bacteria living inside a protective matrix they build themselves. It sheds cells into the water continuously — into the kitchen tap, the shower, the bucket your child bathes from.
Chlorinated municipal supply does not prevent it. The chlorine residual is gone within a day in a warm tank, and the film shields whatever is already growing underneath.
Scrubbing makes it worse over time. Every clean leaves micro-scratches in the plastic, and rougher plastic gives the next colony more to hold on to. A plastic tank is never as clean as the day it was installed. It only gets easier to foul.
Check whether your tank is at risk- Hours 0–24
Attachment
Free-floating bacteria from the supply line settle onto the wall. Scratches left by the last brush-clean give them their first foothold.
- Days 2–5
Colonies
Cells multiply and secrete a sticky matrix. Light through the wall lets algae join in, and the inside turns faintly green.
- Weeks 2–4
Slime layer
The film thickens into the slippery coating you can feel. Chlorine in the water can no longer reach the cells inside it.
- Month 2 onward
Shedding
The mature film sloughs clumps of bacteria into the stored water — continuously, until the next clean, when the cycle restarts.
Why it matters
What lives in the slime — and why nobody traces it to the roof.
The recurring stomach upset, the child's ear infection, the skin rash that clears up on holiday and returns at home. Warm, stored, biofilm-lined water is where these organisms do best.
Pseudomonas aeruginosa
A biofilm specialist that thrives in warm stored water. Linked to skin, ear and eye infections — most common in children who bathe in it daily.
Legionella
Multiplies in water held between 25 and 45 °C — a plastic terrace tank in summer, exactly. Inhaled through shower spray, not swallowed.
"But our water is chlorinated."
It is — at the treatment plant. By the time it has sat for a day at 40 °C in your tank, the residual chlorine is spent. And chlorine works on free-floating cells; it cannot penetrate the slime matrix of an established biofilm. That is why water can test clean at the municipal main and fail at your kitchen tap.
The WHO identifies household storage as a principal point of recontamination for otherwise safe drinking water, and recommends opaque, smooth, non-porous containers that can be fully drained and cleaned. Source: WHO, Guidelines for Drinking-water Quality, 4th ed.
Problem, answer
Five reasons a plastic tank can't stay clean. Five ways steel ends each one.
Plastic tankAquaVigil SS 304
The wall lets light through
Polyethylene is translucent, even in dark colours. Light plus water plus warmth is the recipe for algae — and algae feed the bacterial film.
Completely opaque
Stainless steel transmits zero light. Without light there is no photosynthesis, no algae, and the film loses its main food source before it starts.
It cooks in the sun
Dark plastic absorbs heat, and the water in a terrace tank gets uncomfortably warm in summer — right in the range where bacteria multiply fastest.
Insulated mirror finish
AquaVigil's heat-reflecting mirror finish bounces sunlight off instead of soaking it up, so the water stays cooler through the day.
Cleaning scratches it
Every brush-clean roughens the plastic. Rougher walls give the next colony more to anchor to, so the tank fouls faster every year.
Mirror finish, non-bacterial
Mirror-finish 304 steel gives a film nothing to grip, and it doesn't scratch the way plastic does — so it stays as smooth as the day it was installed.
It ages, pores and leaches
UV makes plastic brittle and porous. Pores hold film that no scrub reaches, and aged plastic leaches — the faint chemical taste in summer water.
Food-grade, toxin-free 304 steel
Safe enough for milk, food and medical storage, and for RO plants. No pores, no leaching, no taste, and it doesn't age in sunlight.
Someone has to climb in
A plastic tank is cleaned by a person with a brush, twice a year if you're diligent. In between, the film returns within weeks.
100% bottom clean
The easy-clean design drains and rinses out completely from the bottom — no partial cleans, and nobody scrubbing inside the tank.
60-second check
Is your tank at risk?
Switch on every statement that is true of the tank on your roof.
Comparison chart
Steel: the safer choice, point by point.
Steel costs more up front and we say so. Here is everything else.
| Criteria | AquaVigil SS tank | Plastic tank |
|---|---|---|
| Water quality | Hygienic | Toxic |
| Growth of algae | No | Yes |
| Smell / change in taste | No | Yes |
| Heat absorption | No — reflective mirror effect | Yes |
| Food grade | Yes | No |
| Medical, milk & food storage | Yes — safe | No |
| Cleaning | 100% bottom clean | Partial |
| Eco friendly | Yes | No |
| Life span | Long | Short |
| After-use value | Very good | Almost nil |
| Cost | Cheaper in the long run | Expensive in the long run |
Built, not moulded
Every part is there to keep the water clean.
01
Wide manhole with stainless lid
A 15.5-inch manhole (12-inch on horizontal models), wide enough to see and reach inside, closed with a stainless steel lid that keeps out dust and light.
02
304 stainless, 0.6 mm, insulated mirror finish
Rolled from 304L stainless steel sheet and finished to a mirror polish. The finish reflects heat instead of absorbing it, and leaves bacteria and fungus nothing to grip.
03
Ribbed, leak-proof shell
Rolled stiffening ribs strengthen the shell so it holds its shape for life: strong, leak-proof, and resistant to corrosion and weather.
04
Bottom outlet, 100% bottom clean
A 1-inch inlet and outlet (1.5-inch on the 3000 and 5000 L horizontal models) and a design that cleans out completely from the bottom. A water-level control switch is available.
05
Strong stand, 304 stainless legs
The stand lifts the tank clear of the roof, keeps the outlet within reach and lets air move underneath. Its legs are 304 stainless steel too.
Sizes and dimensions
Pick the size. We send the best offer on WhatsApp.
Vertical tanks from 250 to 5000 litres, and horizontal tanks from 1500 to 5000 litres for roofs with limited headroom.
500L
Couple or small flat, 2–3 people
- Height
- 63″
- Diameter
- 28.5″
- Tank weight
- 24 kg
1000L
Family of 4–5, independent house
- Height
- 67″
- Diameter
- 38.5″
- Tank weight
- 35 kg
1500L
Joint family, 5–7 people
- Height
- 73″
- Diameter
- 48.5″
- Tank weight
- 44 kg
2000L
Large home or duplex, 7–10 people
- Height
- 85″
- Diameter
- 48.5″
- Tank weight
- 51 kg
- Low model
- 74″ × 54″
3000L
Villa, small apartment block, clinic
- Height
- 87″
- Diameter
- 63″
- Tank weight
- 105 kg
5000L
Apartments, hotels, industry
- Height
- 124″
- Diameter
- 63″
- Tank weight
- 130 kg
Full dimensions, all models
| Litres | Height | Diameter | Manhole | Outlet | Inlet | Tank weight |
|---|---|---|---|---|---|---|
| 250 | 40″ | 24″ | 15.5″ | 1″ | 1″ | 13 kg |
| 300 | 42″ | 28.5″ | 15.5″ | 1″ | 1″ | 15 kg |
| 500 | 63″ | 28.5″ | 15.5″ | 1″ | 1″ | 24 kg |
| 1,000 | 67″ | 38.5″ | 15.5″ | 1″ | 1″ | 35 kg |
| 1,500 | 73″ | 48.5″ | 15.5″ | 1″ | 1″ | 44 kg |
| 2,000 | 85″ | 48.5″ | 15.5″ | 1″ | 1″ | 51 kg |
| 2,000 low | 74″ | 54″ | 15.5″ | 1″ | 1″ | 51 kg |
| 3,000 | 87″ | 63″ | 20.7″ | 1″ | 1″ | 105 kg |
| 5,000 | 124″ | 63″ | 20.7″ | 1″ | 1″ | 130 kg |
| Litres | Height | Diameter | Length | Manhole | Outlet | Inlet | Tank weight |
|---|---|---|---|---|---|---|---|
| 1,500 H | 59″ | 51″ | 60″ | 12″ | 1″ | 1″ | 57 kg |
| 2,000 H | 59″ | 51″ | 78″ | 12″ | 1″ | 1″ | 79 kg |
| 3,000 H | 64″ | 56″ | 85″ | 12″ | 1.5″ | 1.5″ | 91 kg |
| 5,000 H | 76″ | 65″ | 105″ | 12″ | 1.5″ | 1.5″ | 153 kg |
All dimensions in inches; weight is the tank alone, without stand. Price depends on capacity, stand and delivery location — send us your size and we'll quote on WhatsApp.
How it works
From enquiry to running water.
- Step 1
Send your size on WhatsApp
Tell us the capacity and your location. We reply with the price, stand options and a delivery date.
- Step 2
Choose stand and fittings
Add the strong stand with 304 stainless legs and, if you want it, a water-level control switch.
- Step 3
Delivery and installation
The tank is light, easy to handle and easy to install — ready to connect to your inlet, outlet and overflow.
- After
Warranty and lasting value
1-year warranty against manufacturing defects. And unlike plastic, stainless steel keeps real scrap value at the end of its life.
Certified and trusted
Certified quality, and safe enough for milk.
AquaVigil is ISO 9001:2015 certified, associated with the India Water Quality Association, and carries the IndiaMART Trust Seal.
Homes & apartmentsDrinking and household water that stays clean and cool.
RO plantsPurified water stays pure in food-grade storage.
Milk & foodFood-grade 304 steel, safe for milk, food and medical storage.
IndustryWeather- and corrosion-resistant for commercial and industrial use.
Straight answers
Things people ask before they buy.
Didn't find yours? Ask on WhatsApp — a person answers, usually within the half-hour.
Ask a questionCan't I just clean my plastic tank more often?
You can, and it helps for a few weeks. But the film returns within a month in a warm, lit tank, and each scrub leaves the plastic rougher, so it fouls faster next time. Cleaning fights the symptom. Opaque, smooth, inert steel removes the cause.
Doesn't chlorine in the supply kill it?
Chlorine kills free-floating cells. It cannot penetrate the slime matrix of an established biofilm, and the residual is spent within about a day in a warm tank anyway. This is why water can test clean at the municipal main and fail at the kitchen tap.
Is it really safe for drinking water?
Yes. 304 stainless steel is food grade and toxin-free — safe enough for milk, food and medical storage. Nothing leaches from it, and bacteria and fungus have nothing to grow on. AquaVigil is ISO 9001:2015 certified.
Won't stainless steel rust?
AquaVigil tanks are 304-grade stainless steel, the grade used for milk and food storage. Its chromium forms a protective surface layer that resists corrosion and weather, so the tank is built to sit outdoors on a roof for life.
Does the water get hot on the terrace?
Less than in a plastic tank. The insulated mirror finish reflects sunlight instead of absorbing it, where a dark plastic tank soaks up heat all day.
What warranty do I get?
1 year against manufacturing defects. Beyond that, the tank is built for lifelong durability: leak-proof, and resistant to corrosion and weather.
Which sizes are available?
Vertical tanks in 250, 300, 500, 1000, 1500, 2000, 3000 and 5000 litres, and horizontal tanks in 1500, 2000, 3000 and 5000 litres. Full dimensions are in the size table above.
Can I use it for an RO plant, milk or industry?
Yes. The tanks are suitable for RO plants, drinking water, milk and industrial use.
Is a stand or water-level switch available?
Both. A strong stand with 304 stainless steel legs is available, and so is a water control switch.
Ready when you are
The last water tank you'll ever buy.
Upgrade your water. Upgrade your life. Send us your size and location, and we'll reply on WhatsApp with the best offer.