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Outside only, never inside

Exterior Water Tank Cleaning in Toowoomba

Rainwater tank exteriors across Toowoomba and the Darling Downs. Algae, lichen, red dust and cobwebs washed off Colorbond, Aquaplate and poly tanks, with the inlet sealed first so nothing we use goes near your stored water.

Where the line is

We clean the outside. We do not go inside your tank.

Nobody else in Toowoomba lists this as a service, which is odd for a region where most properties past the edge of town have at least one tank standing in the weather.

Two very different jobs get called tank cleaning, and it is worth being clear which one this page is about.

We do not desludge tanks, we do not enter tanks, and we do not touch your stored water. That is confined space work on a potable supply and it belongs to a specialist. If that is what you need, we will say so and you can book the right trade.

What we do clean is everything on the outside: the walls, the top, the stand, the pad, the diverter and the pump housing. On most rural blocks around Toowoomba that has never been done once.

Before we touch a tank, the inlet, overflow and vents are sealed. Nothing we use goes anywhere near your stored water, and if you would rather we did not work on the tank at all while it is your only supply, say so and we will schedule around it.

What a tank clean involves

What a tank clean includes

Tank wallsColorbond, Aquaplate and poly washed at low pressure. Algae on the shaded side, red dust on the western face, and the lichen that establishes along the corrugations and ribs.
Tank top and inletThe top collects everything the roof sheds. Cleaned with the inlet, overflow and any vents sealed first, so nothing we use can find its way into stored water.
Stand and baseTank stands hold moss where they stay permanently damp, and that is what rots timber and rusts steel. Cleaned and treated at the same time, because it is the part that actually fails.
First-flush diverterChecked and cleared while we are there. A blocked diverter is exactly why the first dirty water off the roof ends up in the tank instead of on the ground, and most people have never looked at theirs.
Pump housing and pipeworkWashed down and cobwebbed out. We do not touch electrical connections or plumbing fittings — that is a licensed trade and we are not it.
Tank pad and surroundsThe concrete or gravel pad cleaned back, so the tank is not sitting in a permanently damp collar of growth against its base.

Why one contractor

One booking, one crew, no coordinating

Tanks are almost always booked with whatever feeds them — the house roof, the shed, and the gutters in between.

That is not upselling, it is sequencing. The downpipes have to come off for roof work anyway, and while they are off is exactly when the tank top can be cleaned without anything washing into it.

On acreage, getting anyone to drive out for one small job is the hard part. Four jobs in one visit is what makes it worth everyone's time, and we do not charge travel anywhere in our service area.

Pricing

What affects your tank cleaning quote

Send a photo of the tank and tell us roughly how many litres. We quote the job, not an hourly rate.

How many tanks, and how bigOne slimline against the house is a different job to three 22,000 litre tanks on a rural block. Multiple tanks in one visit are cheaper per tank than any of them alone.
Access and groundA tank tight against a fence or up on a high stand takes longer than one standing clear. Soft ground after rain changes what we can get near it.
How long since it was doneMost tanks have never been cleaned, so the first one is the heavy one. Established lichen on the ribs takes a treatment and dwell time rather than a single pass.
Roof and shed as wellTanks are almost always booked with the roof or shed that feeds them, because the downpipes have to be disconnected for that work anyway. Doing both at once costs less than two visits.
Soil removalOld fill, built-up material or regrading a bed back to level.
AccessWhether we can get a trailer close, or everything has to be carried out.

Deciding

Worth doing, or leave it?

Most rural properties end up booking the tank alongside the shed or the house, because the crew is already on site with the soft wash gear and the water. We will tell you honestly which parts of the tank actually need doing rather than quoting the lot because it is all one structure.

A clean tank is not just about how it looks, though on a tank sitting next to the house that counts for something.

The stand and the base are the real argument. Growth holding moisture against a steel stand or a timber bearer is how those fail, and replacing a stand under a full tank is a far bigger job than washing one.

If the tank is rusted through at the base or the stand is failing, a wash will not help and we will tell you so rather than take the job. On a poly tank that has gone chalky and brittle from twenty years of UV, the same applies.

In their words

What tank cleaning clients say

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Common questions

Water tank cleaning FAQ

Do you clean inside the tank as well?

No. We clean tank exteriors only. Internal cleaning and desludging is confined space work on a potable water supply and belongs to a specialist with the right equipment and certification. If that is what you need, we will tell you plainly so you can book the right trade instead of paying us for the wrong job.

Can anything you use get into my drinking water?

Not the way we set up. The inlet, the overflow and any vents are sealed before we start and stay sealed until the rinse is finished and the tank is dry. If the tank is your only water supply and you would rather we did not work on it at all, tell us and we will do the shed and the roof and leave the tank alone.

Why does my tank go green on one side only?

Shade and moisture, the same as everything else in Toowoomba. The southern face of a tank never gets enough sun to dry properly, and at 700 metres the dew sits until mid-morning. The western face gets the opposite problem — UV and red dust driven on by the westerlies. Two different marks on one tank, needing the same treatment.

Will pressure cleaning damage a poly tank?

It can, particularly on an older one. Poly goes chalky and brittle with years of UV, and high pressure on a degraded surface scours it further and makes it hold dirt faster. Colorbond and Aquaplate have a coating that abrades the same way. Both get soft washed, not blasted.

Do you check the first-flush diverter?

Yes, and it is worth having someone look at it. A blocked diverter is the reason the first dirty water off the roof ends up in the tank rather than on the ground, and most people have never checked theirs. We clear it and tell you what we found.

How often should a tank exterior be cleaned?

Every three to five years is plenty for most tanks. The exception is the stand and base, which are worth looking at more often because that is the part that actually fails. If your tank sits under trees or on the shaded side of a shed, closer to every two or three.

Do you touch the pump or the plumbing?

We wash the housing down and clear the cobwebs out of it. We do not touch electrical connections or plumbing fittings. That is a licensed trade and we are not it. If something looks wrong while we are there, you get a photo and a plain description, not an opinion dressed up as a diagnosis.

Are you insured for work on a rural property?

$20 million public liability, Working at Heights certification, White Card, police-checked crew and a signed safe work method statement on every site. Certificates of currency on request. No other exterior cleaning business in Toowoomba publishes a cover figure — see our compliance documents.

What does exterior tank cleaning cost?

It depends on how many tanks, how big, how they are standing and how long since anyone last looked at them. Tanks are rarely booked on their own — most people add them to a shed or roof clean, which is much cheaper than a separate visit. Call 0490 397 740 or send a photo.

Send photos of the tank and we'll give you a firm price on 0490 397 740 — get a free quote →

Get in touch with James

Free tank cleaning quote

Tell us the tank size and material and when it was last done, and we will give you a firm price before anything starts.

Phone0490 397 740Talk to James directlyEmailjames@topwash.auSend photos of the tank and its stand
Area coveredToowoomba + 35kmNo travel surcharge
WasteAll removedSludge taken away, not tipped on site

Request a free quote online

Tell us the tank size and material, and attach a photo of the inlet and access hatch.

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Tank fed off a dirty roof? See roof cleaning →