How to Build Your Own DIY Fish Tank – A Step by Step Guide

Fishkeeping is a hobby enjoyed by millions of people around the world. Seen as a calming and mostly sedentary pursuit, it has captured the hearts of people from all walks of life and age ranges. Although the hobby can be great to aid relaxation and boost mental health, it can also be pretty costly. Purchasing fish to keep in a tank is the final stage of the process. But, before you get this far, you need a lot of equipment to ensure the safety and happiness of your fish. Costs also depend on the fish species you want to keep, so the overall dent in your pocket can be substantial.

Instead of shelling out fistfuls of dollars on an expensive aquarium tank for your little friends, why not attempt to build your own DIY fish tank? It’s a fraction of the cost and is a really satisfying endeavor. There are few better feelings than being able to show off your stocks AND be able to say that you built them a custom tank. Also, having control of the tank dimensions can make it much easier to fit in that awkward space in the lounge you have your eyes on.

We’re going to have a look at exactly what you’ll need to build your own custom made fish tank, what to look out for in terms of materials, and how you can create an aquarium tank to be proud of.

DIY Fish Tank – Planning

Before you go anywhere near making measurements or looking at materials, you need to decide what type of custom tank you’re going to build. Are you looking to keep freshwater fish? If so, how many? Would you prefer a large reef tank with lots of accessories and live plants to keep your fish company? There are many questions you must be able to answer before you can make any progress.

If you’re starting out in your hobby, it might be that you’re looking to practice with a 5-gallon fish tank. If you’re an established fish keeper already, maybe you’re looking to expand and build a larger tank than you have already in order to progress to the next stage. Think ahead to what you plan to do with the tank and what you’d like to keep in it, and then you can make an informed choice about your next moves. You can also look online or your local store for other fish tank designs and take your inspiration from there.

Also read – What Are the Best 5 Gallon Fish Tanks?

Custom Tank Dimension

As previously mentioned, before you can order any materials or even think about pushing forward, you need to decide what size your DIY fish tank will be.  When it comes to custom fish tanks, not all are created equal. Although, traditionally, most were glass tanks and either square or rectangular in shape, these days many utilize acrylic as a substitute. Also, you don’t have to stick with convention and build a vertical tank which is square. You could break the mold and go for a triangular tank, if you really wanted to. When it comes to custom aquariums, there are no rules – you can design and build whatever you desire.

The materials you use are entirely up to you, but you must consider the cost as acrylic tanks tend to be more expensive than regular glass tanks. If you’re a complete beginner, glass aquariums are likely your best bet, as glass doesn’t scratch as easily. It can be pretty difficult to appreciate the beauty of your fish when you’re peering through an acrylic tank that’s been badly scratched while you were assembling it. Acrylic can also become stained by chemicals within the aquarium, and yellows with age, which tends not to be an issue for glass. Acrylic is the lighter material, so it’s a more appropriate choice for massive aquariums (such as a 200-gallon tank, for example). This generally means it’s not often opted for by beginners who start off with small custom tanks and work their way up. Glass tends to come in a small of standard sizes, whereas acrylic has a wider choice and can be an excellent way to really customize your aquarium tank and ensure it’s totally unique.

You don’t have to choose glass just because most people do. However, if you decide to go with acrylic, you must keep its particularities in mind. For instance, take a look at the following video to see how to glue acrylic properly:

Irrespective of the material you intend to use, you need to measure up the space and decide what size your aquarium tank is going to be. Whether you base this on traditional sizing dimensions to make it easier to buy suitable equipment, such as filtration systems, or heaters, the choice is yours. It might be that your dimension is chosen to fit into a specific space in your home or office, therefore, you’ll be custom-making your own design. Whatever your plans are, measure, measure, and measure again. Also, bear in mind that your glass must fit into your custom tank base and not simply fit in around the edges.

When it comes to aquarium tank glass and acrylic, it tends to come in sheets of the following basic dimensions:

  • Up to 12 inches tall and 0.2 inches thick
  • From 12-24 inches tall and 0.4 inches thick
  • From 24-32 inches tall and 0.8 inches thick

If you stick to these general ratios, it will allow you to make your choice based on the size of your aquarium tank and what you might need, depending on water pressure. The larger the tank, the higher the pressure.

Although the sizes are general, that’s not to say you have to stick with these. You can easily buy large glass panels and then have them cut to the size you want. Having the choice is one of the best aspects of building your own aquarium.

Also read – Best 30 Gallon Saltwater Fish Tanks

DIY Glass Cutting

If this is your first attempt at building your own DIY fish tank, you might want to have a go at cutting the glass on your own. This takes quite a bit of precision, so you’ll need practice before you attempt the real thing. There’s no sense in wasting sheets of glass while you hone your skills. Buy more than you need for your project and use the spare materials to try out your cutting skills and work out what to do.

If this is the road you’ve decided to travel down, you’ll need to get yourself the proper equipment. You’ll need a flat, steady surface to work on, with a protective barrier on it to save it from any damage. It’s also an idea to buy gloves, whether latex or other material. These will stop you from getting your mucky paw prints all over your shiny new glass and can also help to protect your hands a little.

A quality heavy-duty glass cutter will ensure you can achieve accurate cuts along with your original sheets and allow you to shape them to the size you need to build your desired aquarium tank. In order to ensure razor-straight lines and no slipping, a metal ruler is a great aid to use as a guide to cutting the glass sheets.

In terms of technique, you need to have the confidence to go for the cuts and not hesitate. The more you hesitate, the more chance you have of making your cuts uneven, and this will cause problems when you come to assemble your custom aquarium. Use the edge of a sturdy table or countertop to allow you to separate the cuts without danger of damaging the glass. DIY glass cutting can seem a little intimidating at first, but it’s not so bad once you have a bit of practice under your belt.

Take a look at this video for a visual guide on how to cut the glass for your tank:

Obviously, if you’re not confident enough or don’t have the time to do the cutting yourself, then find a local glass cutting service and tell them what you need. All they’ll need are your dimensions and materials, and they’ll take care of the rest for you. They can help you design and build your own custom tank from scratch.

Assembling your Custom Tank

Once you have your glass or acrylic cut into your specified sizes, you need to begin the process of building a tank and putting everything together. You’ll need fish tank silicone to seal the glass together, your base, a caulking gun, and other bits and pieces, like a lid, if you plan on having one. The internal equipment, such as your filter (which could be a DIY filter, if you so choose), live plants, and other accessories come later.

Firstly, put down some sort of protective layer across the surface you’re working to make sure you don’t damage anything. Glass is heavy and tables tend to scratch easily. A cutting board, used for dressmaking, or anything hard wearing will suffice. Start by sanding down any rough edges on your glass tank edges to ensure all panels will fit flush together. You’ll get the best sense of this by setting the panels up how they will look when finished. This will give you a steer of anything that needs to be done and where the bulk of the sanding (if any) needs to be carried out. At this stage, you should also wipe down the surfaces and edges with an alcohol rub or wipe to remove any dirt that may stop the sealant from properly adhering to the surfaces.

Make sure your aquarium glass panels fit snugly into your base and then take each piece, one by one, and use duct tape to protect around the edges from being spoiled by the silicone you will use to join. Gloves will also help you prevent getting your fingerprints all over the surfaces. The outside might be easy to clean, but the inside isn’t. If you’re unfamiliar with a silicone caulking gun, it’s worth testing on cardboard or other materials before you start on the glass. Once you’re confident enough, put together two of the panels and do one corner at a time. This ensures you can get each piece done and take your time to get every individual corner right.

Also read – Self Cleaning Fish Tanks That Actually Work

If you need to secure the corners of your custom tank to help them fix and dry, you can push something heavy against the structure, just until it sets. Leave the first corner until it’s completely set, and then you can go to work on joining the others in place. Once you’ve attached all four corners, leave the entire structure overnight so it can fully harden and gel together. This may be dependent on the manufacturer’s instruction, so check the guidelines on the silicone you’re using.

After leaving adequate time for the silicone to fully set, you can remove the duct tape and scrape off any excess material from the glass tank, both inside and out. With this done, you can attach the base, or slide the glass walls into the base, depending on your set up.

Does my custom tank need a lid?

Having a lid isn’t essential, but it is a good way to protect the fish and water from becoming contaminated by random detritus in your home. It can also finish off the look and feel of your glass tank. If you plan on using a lid, it obviously needs to be cut to your dimensions, but you also want to make sure it’s easy to attach and remove. The lid is your way into the tank for cleaning and all other maintenance, so having a lightweight and easy-to-remove lid is key. If your DIY fish tank is in a standard size, it can be easier to attach a pre-made plastic lid to make life a little easier.

If you can’t find a pre-cut lid, you can always make your own DIY aquarium lid from plastic sheets and cut them to fit the dimensions of your tank. As long as you ensure it fits snugly and can easily be removed so as not to disrupt your fish too much.

DIY Fish Tank: Common Issues

Even if you measured all your panels multiple times and cleaned everything thoroughly, mistakes will happen. This is particularly true if it’s been your first time designing and assembling a custom aquarium. It might be that, when you come to fill the glass tank with water, you notice some water leakage. Simply check where the water is coming from and go through the process of emptying the aquarium tank, resealing it, and trying again. Whatever the issues are you locate in your custom tank, they can usually be rectified without too much trouble. Plus, these mistakes will help you gain experience and knowledge to continue building custom tanks in the future.

DIY Custom Tank – Frequently Asked Questions

Can I use the same silicone sealant I used to assemble my custom tank to glue down accessories in the tank? Yes, depending on which brand you use. Generally, you can use the same silicone sealant you used to hold together your glass tank for gluing down internal accessories, such as ornaments. Always check the instructions before using and ensure you leave the silicone to fully cure before you put fish in the custom tank.

Can I make my own accessories for my fish tank? Yes! If you’ve mastered the planning, building and assembly of a custom tank, there’s nothing to stop you taking it further and crafting your own accessories to make your tank even more unique. A variety of materials can be used, but do ensure that coatings and coverings are safe for your fish.

You should steer away from using metal – even if this has a coating on it. With the amount of moisture, it will be exposed to in your glass tank, it won’t last for any amount of time and will only degrade and look bad. In terms of natural and organic materials, this is entirely dependent on what they are made up of. You must watch for anything containing pesticides, which will mess with your filtration system and harm your fish. It’s also a good idea to steer clear of anything that isn’t usually found in an underwater environment. For example, if you have a freshwater tank, using items found in saltwater locations won’t be compatible and vice versa.

Can I add fish to my DIY fish tank as soon as it’s built? In a word, no. Once you put water in your custom aquarium it needs to stabilize and rid itself of chloramines and chlorine before you introduce your fish to it. This process generally takes around 24 hours, but you can speed it up by introducing a good water conditioner. Either way, not letting your tank water stabilize can be very harmful to your fish stock.

Also read – Everything You Need to Know About Building and Maintaining a Koi Pond

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