5 Hidden Aquarium Cave Ideas You Can Try!

Estimated read time 7 min read

Fish use caves to hide, spawn, or spend the day if they’re nocturnal. If your fish need places to hide, I have several excellent aquarium cave ideas for you.

Some options include a cave with steps, a ceramic jar, a swim-through stone pile, a tree stump cave, and DIY slate rocks.


Top 5 Aquarium Cave Ideas to Choose from

There are several types of aquatic animals that are timider than others or appreciate having a place to hide:

  • Angelfish
  • Axolotls
  • Blind cave tetras
  • Cichlids
  • Catfish
  • Crawfish
  • Discus
  • Loaches
  • Peacock eels

Of course, this isn’t an exhaustive list, but if your fish seem overly stressed and hide out in strange places like between the glass and the heater, you might have a species that would benefit from a cave.

You’ll want to consider the size of the fish in your tank who will be using the cave before you buy one. Discus and angelfish aren’t going to fit in some of these caves because the openings are too small.

Here are some of my favorite caves for fish to hide.

Shale Cave and Steps

Penn-Plax Reptology Shale Scape Step Ledge & Cave Hideout – Decorative Resin for Aquariums & Terrariums – Great for Reptiles, Amphibians, and Fish – Large

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I really like the shale cave with steps because it provides more interaction than most caves. Plecos, crawfish, and any amphibians in your tank can spend time on the steps, while others use it for swimming through or for hiding.

If you look at the pictures of this cave, you will see an entrance at the top and an opening that goes all the way through the bottom of the cave. This design allows quick escapes. It also allows some fish to linger up top while others remain closer to the bottom.

The whole structure measures 8.25” long, 11” wide, and 4” high so that it will take up a good portion of your tank. It won’t even fit in some smaller tanks, so be sure you measure your tank before deciding if it will work for you. There are also some sharp edges you’ll want to file down before putting it in your tank.

Ceramic Jar Cave

Norgail Ceramic Jar Aquarium Decorations Fish Tank Cave Breeding Cones Cave Fish Tank Ornaments for Amano Shrimp Cichlid Bonsai to Play, Hide and Rest

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A ceramic jar cave is a fun addition to your tank, whether you have an underwater city theme or want it as a singular decoration.

There are three openings in the ceramic jar cave, so even if your fish are hiding in it, you can still see it. In addition to the jar mouth, there are also two other holes to allow accessible entrance and egress.

I like the decorative elements on the jar that make it feel a little fancier than some ceramic jar tank decorations.

The jar is 3.15” long, 2.56” wide, and 2.56” high, so it’s only appropriate for smaller fish that need a hiding place. As your cichlids, catfish, loaches, or other fish get larger, they will outgrow this jar.

Swim-Through Stone Pile

Blue Ribbon 006090 Exotic Environments Swim-Through Stone Pile, Large

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If you have a lot of hiders in your tank, a pile of round swim-through stones may be just what you need. It can also help even out some aggression when each fish can stake out their territory.

I like that the openings vary, so some bigger fish can’t antagonize smaller fish as quickly. I also like that the swim-through element allows fish to escape the meanies in the tank if they need to. Plus, I can still enjoy my fish because they’re highly visible from their hiding holes. I like using it in my axolotl tank since each one needs one or two places to hide.

The dimensions for the whole structure are 11.25” x 6.25” x 6.5”. Thus, it takes up too much floor space in a nano tank. However, it’s perfect for larger aquarium sizes.

Tree Stump Cave

AQUA KT Aquarium Landscaping Tree Stump Hole Rock Cave Cichlid Stone for Fish Tank Decoration

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The tree stump cave is resin rather than wood, but I think it looks like a great piece of driftwood. It can fit with nearly any theme you have in your tank, from something whimsical to something more natural.

This cave is one of my favorites in my cichlid tanks. Even if all the other decorations are natural stone, it doesn’t look out of place. It also provides a bit of greenery that they can’t dig out or chew. I like that it allows for a swim-through shelter and multiple places up top and around the roots to hide. It’s not uncommon for my pleco to be eating algae up one side, my catfish to hide out around the roots, and three cichlids to nestle in other crevices–all in peace.

At 4.72” long and 5.12” high, it will fit in almost any size aquarium you have.

Natural Slate Rocks

Voulosimi Natural Slate Rocks 3 to 5 inch PH Neutral Stone Perfect Rocks for Aquariums, Landscaping Model,Tank Decoration,Amphibian Enclosures (10 lbs)

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Slate allows you to make caves and tunnels to fit the specific needs that your fish have. This option is ideal if you have larger fish like discus, angelfish, and larger cichlids that appreciate a place to hide.

The nice thing about choosing slate is that it’s perfect for building walls as roofs. Unfortunately, the first time I made caves for my fish, I made the mistake of buying random rocks in the aquarium store. It was only when I got home that I realized I had nothing appropriate for making roofs and had to search around town for someone who sold slate.

Voulosimi sells five different slate options:

  • 7 pounds of 3” to 5” pieces of slate
  • 10 pounds of 3” to 5” pieces of slate
  • 3.5 pounds of 5” to 7” pieces of slate
  • 7.5 pounds of 5” 5o 7” pieces of slate
  • 12 pounds of 5” to 7” pieces of slate

For reference, a 10-pound order should include about 15 or 20 rocks. I suggest you buy shorter pieces for stacking and more extended parts for roofs. Some people glue them together to create caves that won’t collapse when they vacuum the tank which is a great idea because my axolotl likes to hide when I’m cleaning the tank.

If you’re able to make a cave big enough it might look cool if placed some Shipwreck aquarium decor inside or even a Pirate Ship.

Video: How To Make Aquarium Caves


No matter your theme or fish size, you should be able to find some excellent aquarium cave ideas from my list of favorites. My go-to favorites are the tree stump cave and natural slate rocks since both have a natural look and provide lots of hiding options for a variety of fish in your tank.

There are so many fish tank decoration ideas out there, but none are more valuable than caves.

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