Planted Aquarium Tank Dimensions

by Apr 3, 20209 comments

How to Determine Your Planted Aquarium Tank Dimensions

After choosing the ideal location of your aquarium at your home and the stand to be used, you have to determine your planted aquarium tank dimensions. You have to take measurements of the Length, Width, and Height (LxWxH) of the stand. Take into consideration where you will put your equipment, tools such as aquarium filter, aquascaping tools (straight tweezers, curved scissors), siphon, etc.

Table of Contents

It Depends on the Location and Chosen Stand
Cost Considerations
Recommended Sizes
Standard Aquarium Dimensions (Rectangular)
Aquascaping Style and Faunas You Want to Keep
Standard Aquarium Dimensions (Cube)
Closing Remarks

It Depends on the Location and Chosen Stand

If you have a custom cabinet made for your aquarium, measure the dimensions at the top of your custom-made cabinet. That is the length and width of your aquarium. You have to decide now the tank’s height that you are comfortable with while doing aquascaping and maintenance. It shouldn’t be a stretch for you to reach the tank’s bottom using your hands and without using any stool or chair.

Custom-built cabinets will allow you to conceal all your equipment (canister filter, co2 tanks, fertilizers, fish food) by putting them inside the compartment/s.

If you have a hardwood table or waist-high flat-top furniture, remember your tank length may not necessarily span the length of the furniture. You can allow space on the sides to organize your tools for quick maintenance/trimming and then put your filter under the table if you have a canister filter.

Aquarium Custom Stand & Cabinet Aquascaped by Fritz Rabaya Philippines

Custom Made Cabinet – Client Tank – Aquascaped by Fritz Rabaya – Philippines

Iwagumi Jay-r Huelar 1

Custom Made Cabinet – Client Tank – Aquascaped by Jay-r Huelar – Philippines

Repurposed Rack Stands by Omar Krishnan Afuang

Re-purposed Rack Stands – By Omar Krishnan Afuang – Philippines

Cost Considerations

Another consideration is cost. As the tank of choice gets larger, the aquascaping materials (substrate, rocks, and driftwood) cost needed for a nice scape will be proportionally higher. Sometimes, even higher than the tank costs itself plus the equipment (filter, lights, submersible pumps).

Some hobbyists bought a large tank and ended up with a half-bare scape because there is no budget anymore.

Aquascaping Materials Les Paul Villanueva Philippines

Aquascaping Materials Les Paul Villanueva Philippines

Recommended Sizes

I recommend long-short tanks [they have more depth (width) front to back than height] as they are easy to aquascape with. 10, 15, or 20 gallons ‘long’ are good choices to start with.

Standard Aquarium Dimensions

Measured in inches (L x W x H):

10 gallon – 20″ x 10″ x 12″

15 gallon long – 24″ x 12″ x 12″

20 gallon long – 30″ x 12″ x 12″

Avoid tall tanks, as you may overexert yourself while doing the designing of your scape or while doing maintenance. Tall tanks also require you to use stronger lighting, which will add to the cost. Light waves decrease exponentially as it travels deeper in water.

There are many standard tanks sizes that you can choose from, or you can find custom tank makers that will build your tank based on your own specifications/dimensions.

Different Aquarium Tank Sizes

Different Aquarium Tank Sizes

Tank Size (Rectangular)
10 gallons
15 gallons long
20 gallons long
25 gallons long
30 gallons long
40 gallons long
L x W x H (inches)
20" x 10" x 12"
24" x 12" x 12"
30" x 12" x 12"
30" x 14" x 14"
36" x 18" x 12"
48" x 12" x 16"

Considering the Aquascaping Style and the Faunas You Want to Keep

The aquascaping style you have in mind also factors in when determining your tank’s dimensions. For example, you can do most aquascaping designs in a 15 – 20 gallon long tank and compliment with nano fish/es, shrimps, snails, etc.

There are aquascaping styles that can be done on cube tanks as well, like Nature, Iwagumi, Biotope, Walstad, Hardscape Diorama, etc. Below, we provide the standard cube tank sizes for those with limited spaces in their homes.

However, suppose you want to preserve the scale of a Jungle or Nature Style aquarium for big fish species like Arowana, Discus, etc. In that case, you need at least 50 gallons for a group of 6 Discus and at least 100 gallons for a single Arowana.

For the ideal tank sizes for each aquascaping style, go here. Choose the style that you want and see the “What Tank to Use” Section.

Tank Size (Cube)
7.5 gallons
10 gallons
15 gallons
20 gallons
25 gallons
L x W x H (inches)
12" x 12" x 12"
13.2" x 13.2" x 13.2"
15.2" x 15.2" x 15.2"
16.7" x 16.7" x 16.7"
18" x 18" x 18"

You would be surprised by some amazing aquascape pictures on the internet that looks like it was done in a large tank, but in reality, they were just done in a 15-gallon or lower tank, like the image below. This was done in a 15-gallon long tank 24 x 12 x 12 by Fritz Rabaya – Philippines. The aquascaper can be called an illusionist. He/She can create a sense of depth, scale, and proportions in a small aquarium.

We can produce great results by focusing our efforts, time, and money on small to medium tanks. 

Hardscape Diorama Style Aquascaped by Fritz Rabaya Philippines

Hardscape Diorama Style Aquascaped by Fritz Rabaya – Philippines

But then the greatest pro of small/nano tanks is also its greatest weakness – water volume. It is volatile and unstable if you don’t know what you are doing. Small planted aquariums are cheap and easier to aquascape (as a beginner, you may/will be doing this a lot when experimenting with different layouts, or you commit a mistake). The problems you may encounter are easier to correct and less costly if you did an oversight, or if you are testing/experimenting with your ideas or theories and it didn’t work.

It is much easier to do plant maintenance (trimming) and less water to change as well on small aquariums. Unless you already did your research, and are very willing to learn, we still don’t recommend small/nano tanks for beginners. The water volume is so small that water parameters can simply go awry in an instant.

You should already have the keen observation and insights on what to do in a specific scenario/problem and should have done the necessary precautions for that problem not to happen in the first place (like overfeeding, overstocking, wrong combination of faunas, tank neglect, overdosing, wrong size filter, wrong lighting, etc.)  – unless you are experimenting.

You will be able to grasp the intricacies of a planted aquarium quickly though when using small to nano tanks. Medium to large tanks simply just give you a certain buffer to get away with mistakes. Also, problems do not manifest quickly on medium to large tanks until you are not certain anymore what you had changed. Rectifying the problem is also the same story, results do not reveal immediately if it solves the issue or not.

No planted aquariums are the same. Not everyone’s experience is the same, regardless of the size of your tank. Do you have the motivation, determination, and dedication to keep a planted aquarium at home? Do you easily quit at the sight of algae infestation? Are you discouraged easily when your plants are not thriving, or your fishes are dying one by one? Are you willing to find out the cause of your problems and rectify them?

Let me tell you this, and this might come as a warning, the first few months might be a nightmare to a beginner if you didn’t do your research first. I am not saying everyone will, but the chances are great. Even for someone who did my research before undertaking this hobby, I still have many downs keeping my planted aquarium. But I love this hobby, and I didn’t quit, and I triumph on every burden that came along the way. Most importantly is that I learned a lot from these experiences.

You are in the right direction by finding this site, and we will help you on your journey with this hobby. We have your back!

Nano Tank 2.5 Gallons Aquascaped by Omar Krishnan Afuang Philippines

Nano Tank – 2.5 Gallons – Aquascaped by Omar Krishnan Afuang – Philippines

Want to Explore More?

The Planted Aquarium Nitrogen Cycle

Yes, I said that this discussion about the Nitrogen Cycle in our aquariums is for beginners. Because it is easy for a beginner to get too excited to set up their first planted tank, set up the filter and lighting, begin aquascaping, planting, filling it with water, putting the fish in, etc., then meet the consequences.

Iwagumi Aquascaping Style

The Iwagumi style is a sub-type of the Nature style we discussed earlier that incorporates the same core principles of Japanese gardening techniques. It is derived from the Japanese art of stone appreciation, Suiseki. Where small naturally occurring or shaped rocks are appreciated for their aesthetic and decorative value.

Lighting a Planted Aquarium

The thing is, as I always mentioned before, every planted aquarium is unique. There are no secret LED or T5 lighting specs, nothing set in stone. Even DIYs can work. There are many variables to consider when determining the proper lighting for your planted tank.

Minerals - The Planted Aquarium Water Parameters

Hardness/softness is the measure of dissolved minerals in the water. But although pH and hardness are different water parameter measurements, they are closely linked to each other.

HOB Filters - Types of Planted Aquarium Filters

They are also called hang-on-back filters (HOB), and are designed to hang on the back of your aquarium, eing! Power filters are the most commonly used planted aquarium filter because they provide good to excellent mechanical and biological filtration simultaneously. They can also provide the needed water surface agitation for aerating your water.

Filter Maintenance Along With Water Change

Contrary to popular practice, some hobbyists will say that you cannot perform filter maintenance along with your water change schedule. That you may kill or wash away a significant amount of your beneficial bacteria when doing so. The only way for this to happen is by using chlorinated tap water or drying out your biological media, or your primary filter is just a sponge filter. Those are sure-fire ways to kill or wash away a lot of your good bacteria.

Safe Water Sources for Planted Aquariums

Your water source should be chlorine or chloramine-free at the most basic of things and should have very little unknowns in it. Remember, you cannot test everything in the water, so your water must be clean with little unknown substances. But to add to the confusion, very pure/clean water is also bad for your plants and faunas, which we will explain below.

Closing Remarks

I hope you enjoyed this article. If you have additional questions or want to share your experiences with how you determined your ideal tank dimensions, please leave a comment below.

Next, we will be discussing the types of aquariums and how it can help you with your decision if you want a Rimless Tank or a Braced Tank.


  1. Selenity Jade

    I used to have a 50 gallon braced tank when I was younger!  I was a teenager and my mom thought it would be cool.  It takes a LOT of work to maintain we realized.  Ours was glass, not acrylic, thankfully.   Still heavy. We definitely got easy freshwater fish.

    Our tank came with a cabinet attached.  That thing was a heavy, giant monster to move or even clean.  And once, when we added a few new fish to our tank, there was a tiny snail in the bag.  We didn’t think that would be a big deal until one snail turned into hundreds!  Holy moly!  The snails were useful, definitely, but they bred out of control!

    Looking into doing an aquarium today, and while I’d love braceless looking ones, I will probably go for a normal glass, braced aquarium.  Though NOT 50 gallon again.  I also think I’m going to pay attention to hidden snails.

    • Lemuel Sacop

      Thank you Jade for sharing your experience with the snail. I have a similar experience, the only difference is that I really bought those ramshorn snails 3 of them, but didn’t researched enough that they breed profusely, they are hermaphroditic, two organisms of any sex have the ability to breed and produce offspring. I came to love these snails, I just pick them out if they get too many and give them to my fellow hobbyist. Please watch out for more articles coming soon. Maybe an article about aquarium snails. You just gave me an idea for another article.

  2. Carolyn

    I enjoyed your article on aquariums. I didn’t know there was so much to learn about them. We had an aquarium when my children were small. My youngest enjoyed it so much that now she has her own. At one time she had multiple aquariums going at one time. Now with a family to care for, she enjoys her one aquarium and my grandchild does as well.

    Just watching fish in an aquarium can have a calming effect on an otherwise stressful day.

    • Lemuel Sacop

      Thank you Carolyn for sharing your experience as well. Please come back for more articles coming soon.

  3. Mugalu Mansoor

    Thank you very much for this detailed article. I found this article very useful as I was planning soon to contruct an aquarium . I really found what i was looking for. I also thank you for theatre hardwork you put in to bring this websites together. I thought my place was small but according to how you explained now i know what exactly to do. Thanks

    • Lemuel Sacop

      Thank you so much that you like this article. Please come back for more articles coming soon. 

  4. Trevor

    I am planning to install a fish aquarium in our next home when we move later this year.  For me, this site is highly relevant and timely. Getting the size of the aquarium right, is clearly a critical part of the process.  As well as choosing the right location. The sort of pragmatic advice you suggest, such as not having to stretch to reach the bottom of the tank, is very sensible. The custom built suggestion is terrific to “hide” all of the necessary equipment. Or if it’s a free standing tank on a table, to ensure you leave space for the essential equipment.  Your recommended sizes is also invaluable.  I am saving your URL for future reference.  Thank you for this excellent resource and advice.

    • Lemuel Sacop

      Hi Trevor, I am really amazed how you noticed those small details and sensible advises that I included in the article and I hope in some way or two, I was able to help you in your decision making in starting up your planted aquarium at home. Please watch out for more articles coming soon.

  5. Aquatech Aquarium Service

    Anybody trying to put up a planted aquarium will find this article to be highly instructive. The article’s thorough explanations and examples make it simple to comprehend why picking the appropriate tank dimensions is essential for the health and growth of your plants. The section on calculating substrate depth was especially helpful to me because I had never thought about it before. I appreciate you sharing your insight and experience on this subject.


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