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How To Easily Make PVC Pipe Aquarium Caves!

With fish keeping being more popular than ever, we often see people new to the hobby reaching out and asking for advice on how they are able to reduce the costs of running their tanks.

One of the quickest, easiest, and cheapest alternatives to potentially expensive tank accessories is to make your own PVC pipe aquarium caves rather than buying caves or fish hides.

With a number of people within the fish keeping space on social media sharing a number of their PVC aquarium cave designs, this is becoming more and more popular too but to get a good looking PVC pipe cave, you will have to put some time and effort in.

If you just want a quick and easy PVC pipe cave then you can make one within minutes but it may not look as good as some of the designs that you have seen on social media.

Can I Put PVC Pipe In My Aquarium?

This is a common question that we often see online and the answer is yes, you can put PVC pipe in your aquarium but there are a few things that you need to consider before doing so.

You need to use professional grade PVC to prevent it from leaking toxins into your tank water, you need to make sure that you have clean cuts on your PVC pipe when making your caves, and ideally, the PVC will not have been used before.

We have seen a number of people using old PVC pipe that has either been used before and had chemicals running through it or is very dirty. Always try to stick to using clean PVC pipe if possible to try and make sure that it is aquarium safe.

Our article on if PVC is safe to use in an aquarium goes into this in more detail if you would like to know more.

What Glue Should I Use To Make PVC Aquarium Caves?

Glue is not essential when making PVC pipe aquarium caves and many people just cut the tube and use it as it.

If you are wanting to make a more elaborate PVC cave for your fish then you will have to use some type of glue.

The type of glue that you use to make your PVC aquarium caves is very important as if you use the wrong glue then it can potentially be harmful to both you and your fish.

You should always use an aquarium safe silicone sealant or glue when making your PVC aquarium caves.

We have articles going over how you can use hot glue for aquariums as well as the best aquarium glue with both being valid options when looking to make PVC aquarium caves.

Do Fish Like PVC Aquarium Caves?

The simple answer to this question is yes, fish do like PVC aquarium caves as they provide a place for them to hide away from the light and other fish in the tank.

Fish are very shy creatures by nature and in their natural environment, they would spend most of their time hiding away to avoid predators.

DIY PVC aquarium caves offer an excellent way to make custom fish hides that can be difficult to make in other ways too.

You are able to attach different shapes and lengths of PVC pipe to make an intricate design for your dish. S bents and C bends can often be buried in your tanks substrate or surrounded by rocks to make semi-realistic caves for your wife too.

How Do You Make PVC Aquarium Caves?

Now that we have looked into some of the questions that you may have about making PVC caves, it is time to look at how you can make your own.

You will need a few tools and supplies before starting out which you can find below but other than that, it is just a case of following the steps.

Tools & Supplies

-PVC pipe

-PVC cutter or saw

-Aquarium safe silicone sealant (optional)

-Aquarium safe glue (optional)


  1. Cut your PVC pipe to the desired length and shape. You can use a PVC cutter or saw for this.
  2. Make sure that any cuts on the PVC are clean and fiber-free. You can run a towel or cloth over it to check and if the cloth catches on any PVC jiggered edges, sand them down.
  3. If you are using glue then apply it to one end of the PVC pipe and attach it to the other.
  4. If you are using silicone then apply it to both ends of the PVC pipe.
  5. Leave for 24 hours to allow the silicone or glue to set before adding the PVC pipe to your aquarium.
  6. Place your PVC aquarium cave into your tank in its intended location to make sure it fits correctly.
  7. Make any required adjustments to your PVC cave if it does not fit in your tank correctly as needed.
  8. If you had to make adjustments involving glue then wait another 24 hours for it to cure fully, if you just had to make simple cuts, add the DIY PVC cave to your aquarium.
  9. Surround the DIY PVC cave with plants, rocks, or substrate if you wish to make it look more natural in the tank.

Your PVC aquarium cave is now ready to be used.

Do I Need To Clean My PVC Aquarium Cave?

You do not need to clean your PVC aquarium cave unless it becomes dirty. If you are using an old piece of PVC pipe then you may want to clean it before using it in your tank but we always recommend you use new PVC.

You can clean your PVC aquarium cave using a mild detergent and a soft brush. Rinse it well afterwards to remove any soap residue.

You should also sand down any rough edges on your PVC pipe before using it in your tank as these could hurt your fish.

Does Aquarium Substrate Degrate PVC?

Aquarium substrate will not degrade PVC but it can discolor it over time. This is not harmful to your fish and is more of an aesthetic issue.

If you are looking to avoid this then we recommend using dark colored aquarium substrates as they are less likely to discolor your PVC pipe.

How Do I Hide My PVC Aquarium Caves in My Tank?

You can hide your PVC aquarium caves in your tank by surrounding them with rocks, plants, or substrate. This will help to make them look more natural in your tank and will also provide some shelter for your fish.

You can also bury part of the PVC pipe in your substrate to make it look more realistic. Just make sure that you leave enough of the pipe exposed so that your fish can still access it.

You can use live plants such as java moss to actually grow over the PVC pipe too as java moss will usually grow on PVC without issue.

Surrounding your PVS pipe aquarium cave with rocks is another popular option as it can make the cave look natural but makes sure that the rocks are not able to fall and crush any fish in the cave as the PVC pipe can protect the fish.