Why Is My Fountain Green and Slimy, and How Do I Clean It?

A fountain is supposed to be the nice part of the yard. Then the water goes green, the bowl gets slick, and a white ring shows up where the water sits. If that is where yours is, here is what is going on and how to get it back.

The Short Version

• Green water or a slimy film? That is algae, and draining and cleaning the fountain is what clears it.
• White rings at the waterline? That is mineral scale, and it usually comes off with the right treatment.
• Worried about damaging old stone or concrete? Methods get matched to the material, and delicate finishes get cleaned by hand.
• How often? Once or twice a season for most outdoor fountains in Delaware.
• Green creeping onto the pavers around it? The surrounding hardscape can be cleaned in the same visit.

Why is my fountain green and slimy?

It is algae, and fountain cleaning, where the fountain is drained, the growth is treated and the buildup is removed, is what gets rid of it.

Standing water grows algae fast in a Delaware summer. Sunlight, warm water and leaves or debris sitting in the bowl give it everything it needs. The green tint is the algae in the water. The slick coating on the bowl and the tiers is the same growth stuck to the surface.

How do I get rid of the green algae in my fountain?

Drain it and clean it out. Our fountain cleaning starts with the feature drained and empty, then we treat the growth, remove the buildup with methods matched to the material, and rinse it so it is ready to refill.

Topping off green water does not fix it. The algae is on every surface the water touches, so it has to come off the stone, not just out of the water.

What are the white rings at the waterline?

That is mineral scale, and it usually comes off with the right treatment during a cleaning.

Water evaporates and leaves its minerals behind at the line where it sits. Over a season that builds into a chalky white ring. Very old, etched-in scale on porous stone sometimes lightens rather than vanishes, and we will tell you which to expect when we see it.

What's the best way to clean an old stone or concrete fountain without damaging it?

Match the method to the material. We clean concrete, stone and resin fountains, and delicate finishes get hand attention, not blast pressure.

Blasting a soft stone or a painted finish with high pressure can do more harm than the algae did. It is the same thinking behind the soft washing we use on houses: use the right amount of force for the surface, not the most force available.

How often does an outdoor fountain need to be cleaned?

Once or twice a season for most outdoor fountains in Delaware. Fountains in full sun or under trees grow algae faster and lean toward twice.

A fountain that only gets cleaned when it is already green is always playing catch-up. Putting it on a schedule keeps it looking the way it did when it was new.

How do I keep my fountain from turning green again?

Keep it on a regular cleaning schedule. Algae comes back as long as there is standing water, sun and warmth, so the goal is to clear it before it builds up, not after.

Sun and falling leaves both speed it up. If your fountain sits in full sun or under a tree, plan on the twice-a-season end of the range.

What about the green on the pavers and stone around it?

That is the same growth spreading out from the water, and the surrounding hardscape can be cleaned in the same visit.

The basin surround, pavers and stonework catch overspray, splash stains and algae creep. Cleaning the fountain and leaving a green ring of pavers around it only gets you halfway. If it has spread further across a patio or walkway, see deck and patio restoration and mold, algae and stain removal.

What does fountain cleaning include?

Fountain cleaning covers the fountain itself and the area around it: freestanding and tiered fountains in concrete, stone and resin, birdbaths and small water features, plus the basin surround, pavers and stonework.

We take care of green algae, black grime and mineral scale at the waterlines. The feature gets drained, treated, cleaned and rinsed ready to refill.

Do you clean fountains for businesses and HOAs?

Yes. Office courtyards, HOA entrances and community features are all welcome.

An entrance fountain is the first thing people see. When it is green, that is the impression it leaves.

What does fountain cleaning cost?

Every job is quoted after we see it, and the quote is free. It comes down to the size of the fountain, how many tiers it has, how heavy the buildup is, and whether the hardscape around it is part of the job.

Who cleans outdoor fountains in Delaware?

We do. CT Clean and Son is a father and son team, and we do the work ourselves.

We cover Wilmington, Hockessin, Newark, Christiana, Greenville, Glen Mills and Garnet Valley, plus the rest of New Castle County and nearby Pennsylvania. We are fully licensed and insured, with a certificate of insurance available on request.

Call (302) 290-6508 or request a free quote.

Providing the cleanest, safest and brightest environment possible for your home or business