Flamingo Crossing

better gnomes and gardens

Tub water gardens -- design, build, and maintain

tub water garden
While you might think a smaller space precludes the enjoyment of a water garden, it doesn't. You can make a water garden from a small tub or half-barrel that would be perfect for a small space such as a patio or deck.

Once your project is complete, you will be able to spend warm summer evenings watching the play of patio lights and fireflies on the moving water of your pond. It's a great way to spend an evening!

How to build a tub water garden

tub water garden What size water garden to build?

If you are building a water garden for a patio, you are limited by the amount of available space. It is of course prudent to build the biggest tub water garden your space and budget allows: the smaller the pond, the more quickly the ecosystem you create can break down. A bigger tub garden is also lower maintenance as water evaporation will empty a tiny water garden faster than a larger one.

If you have space for a slightly larger water garden, a plastic or galvanized steel stock tank can make an excellent water garden.

Choose a water pump for your pond

You will need a pump that circulates all the water in your pond at least once per hour. It's better to buy a bigger pump than you need than a smaller one. If you don't get adequate water circulation, you will have mosquitoes breeding in your pond due to stagnant water.

In addition, if you plan to add fish, they will benefit from a higher water circulation rate.

a bell fountain Choose a fountain for your water garden

While it is not strictly necessary to have a fountain at all, it does add a nice touch to any water garden. The sound of running water is very relaxing and really contributes to the atmosphere. A fountain will also increase the water circulation within the pond.

Tip: Be sure to choose a fountain type that fits with the scale of your pond. For a small tub water garden, this means a simple bell or spray rather than anything ornate. You also might choose a fountain that plays well with any lights in the area.

Before buying water plants and fish

Dechlorinate any water used to fill your pond. Chlorine isn't good for plants and will kill your fish. Use a special filter on your hose when you fill the pond. Then, check the hardness, pH, etc. of your pond with the appropriate test strips. If the readings are outside the safe levels for plants and fish, fix the problems before you acquire your finny friends. Your plants will be happier, too!

Choosing plants for a tub water garden

Brighten up your pond with glorious colours

Adding water plants to your pond will head off algae problems later on. Choose as large a variety of plants as the size of your tub water garden allows. Here are some suggestions:

Emergent plants

  canna lilies

Canna lily
Canna spp.

  umbrella papyrus

Umbrella papyrus
Cyperus alternifolius

  dwarf papyrus

Dwarf papyrus
Cyperus profiler

  cyperus helferi

Cyperus helferi


Floating plants


Lemna minor

  fairy moss

Fairy moss
Azolla spp.


Limnobium laevigatum

  water hyacinth

Water hyacinth
Eichhornia crassipes

  water lettuce

Water lettuce
Pistia stratiotes


Submerged plants


Anubias spp.


Ceratophyllum demersum

  java moss

Java moss
Vesicularia dubyana


For most of your non-floating plants, it is best to pot them hydroponically to avoid getting dirt in your pond. This means removing any potting soil from your plants and potting them up using a small plastic mesh basket and river rocks.

Note: You can't do this with water lilies.

How to pot water lilies

Water lilies need some sort of soil-like medium to grow. Pot them in a small bucket or planter that does not have holes in the bottom, then fill the bucket with aquarium-grade sand. Cover the top with a layer of pea gravel, then carefully sink the planter into the pond so all the sand doesn't rush out.

Choosing fish for a tub water garden

carp How many fish will fit?

For a small pond such as this, your best choice would be a couple of the smaller carp: shubunkins or comets. Shubunkins are calico fish (tri-colour in white, red, and black), while comets are generally considered miniature koi in colouration. They require a minimum of 10 gallons of space per fish, so you can easily calculate the proper number for your pond.

While the fish will happily eat mosquito larvae, you should also provide them with food each day. Pellet type fish food is better than flake fish food for ponds as it makes less of a mess in the pond.

Note: If you are including fish, you will need a filter for them. No fish should be placed into a tank or pond without a filter! Choose a filter that is appropriate to the size of your pond. I use a double filter (that is, twice what would normally be required for that size pond) on any pond that contains carp as they are "messy" and will dirty the water quickly.

How to maintain a tub water garden

If you are adding carp to the water garden, I would suggest adding some Japanese trapdoor snails as a maintenance crew. They can deal with uneaten fish food and control algae overgrowth so the water in your water garden will be crystal clear. These snails when fully grown are about 2" in diameter, typically with a green-brown colouration to the shells. They are peaceful, hard working, and non-aggressive. One or two snails per 25 gallons of water is generally sufficient.

Aside from that, however, a tub water garden tends to be low-maintenance. Top up the water as needed with dechlorinated water if your area isn't rainy.

The Mermaid's Grotto