Indoor Ponds

Indoor ponds function in exactly the same way as outdoor ponds when it comes to keeping the water clean and clear. So all of those directions are the same.

Differences and things you have to be aware of are below:


If you intend to keep plants alive over the winter, you're going to have to have supplemental lighting. In general, you'll find yourself investing in high-intensity grow lights if you really want to grow plants over the winter.

Otherwise, you'll discover that oxygenating plants will lose leaves and create debris on the bottom of the pond. Floating oxygenators will give you the first clue about too-low light levels because they'll stretch and start to look like elongated rather than tight and compact.

Hardy lilies do not require indoor ponds and will want to go dormant. Winter these outdoors.

Tropical lilies will require both warm water and high light levels to keep growing.

An Expensive Way To Overwinter

Frankly, this is an expensive way to overwinter plants - both in terms of purchasing the light units and running them. Note that we're not talking about simple grow lights here but rather commercial level lighting.

Indoor ponds are not the place to overwinter plants. If you want to do this, then a few aquariums with regular grow-light flourescents in inexpensive holders work well.


Indoor ponds are perfect places to overwinter fish. As long as you have full biological filters setup to handle the fish waste, this system is simply an aquarium sitting on a floor that you look into from the top rather than the sides.

The rules about fish densities hold true for indoor ponds (roughly one inch of fish per square foot of pond) unless you're really pumping the water around and increasing the oxygen levels. Then you're talking aquarium levels.


Make sure your floors are solid as water weighs roughly 10 pounds per gallon. It doesn't take much of a pond to put a lot of weight on the floor.

Lay a plastic liner down below all the rest of the construction so that if you spring a leak in the liner or spill water from filling then water isn't going to wind up sitting on your subfloor (and water does terrible things to subfloors). Also drainage water from potted plants will wind up down here as well.

Do this even if you're using a solid plastic pond liner. Trust me, you'll spill water over the edge of the pond at some point or other.


Do plan on surrounding the pond with a wall that matches the rest of your house decor.

And leave space between the pond and your wall for plants. The real trick with plants in indoor ponds is to leave them in their pots and bury the pots into the mulch that surrounds the pond.

Do not use real soil to surround the pond. The weight of this is massive and combined with the pond water, you're asking for trouble. Use peat moss or perlite or some other light material.

Bury your pots into this material and then mulch the top with a decorative rock or garden mulch to disguise the pots.


You're building a pond. The only difference between an indoor pond and an outdoor pond is the size and surrounding landscaping. All other rules of clean water, fish maintenance and filters/pumps etc are the same.

The difference is in the plants you can grow in low light levels indoors compared to outdoors and how you handle those plants (in-ground versus potted).

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Indoor Pond

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