How Many Discus Can I Keep in A 55 Or 100- Or 150-Gallon Tank?

As an easy guide, if you set up a greater or lesser than a 100-gallon tank, you can calculate how many Discus you can keep based on this. A 100 Gallon tank can hold 35 to 40 adult Discus fish if you ensure to clean the tank twice per week, and not overfeed them. A 150-gallon tank can hold 55 to 60 adult discus fish with the same maintenance stated above.

If you wish to put in the work of cleaning your 55-gallon tank and completing a 25% water change twice a week, then Discus stock levels can be between 15 to 18. However, if you are only clean once per week, it should contain just 5 to 6 Discus. 

Note: As a rule of thumb, every Discus requires a space of at least 10 gallons of water, i.e., a 55-gallon tank should have between 5 to 6 Discus for the perfect practices with a 25% weekly water change.

Table of Contents

Can I Keep 1, 2, or 3 Discus?

No, it is not advised to keep 1, 2, or 3 Discus in a tank, especially adult Discus, because they won’t be happy.  at least a 55-gallon tank, with a minimum of 5 to 6 Discus is preferable because Discus live well in groups.

Basically, To create that ideal atmosphere inside your aquarium, you would also need to install plants or accessories and this would take up sufficient space within the tank. With this in mind, it is always better to go for larger-sized tanks that would enable your Discus to move around more freely and in groups.

How Many Discus Can I Put In A 29-Gallon Tank?

You can put 2 Discus in a 29-gallon tank, and this is only for a breeding pair, and they should be fine. Also plan on finding them a larger tank before they get anywhere near 5 inches, they need adequate space to swim in order to be happy.

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How Many Discus Can I Have In A 36-Gallon Tank?

You can have 3-4 discus in a 36-gallon tank, and it is advised to have a breeding pair. As they begin to reproduce, you would have to move to a larger-sized tank in the long run.

Although you might still choose to maintain this tank even with the increase in the number of your Discus, that wouldn’t be ideal.

Note: You would need to change a great deal of water (80-100%) every other day and do a lot of cleaning up.

How Many Discus Can I Put In A 40 Gallon Tank?

You can put 6 or more Discus in a 40-gallon tank. Though you will have to do a lot of cleaning by changing the water daily or feeding them less. however, ideally, you can put 4 Discus in a 40-gallon tank with a weekly 25% water change.

Note: The best practice is to have 5 to 6 Discus in at least a 55-gallon tank with a 25% weekly water change.

How Many Discus Can I Keep in A 55-Gallon Tank?

Ideally, you can stock it up with 5-6 fishes, and do a 25% weekly water change for healthier and happier Discus. You can stock your 55-gallon tank with 15 to 18 adult Discus if you are ready to change the water twice a week,

Note: As a rule of thumb, every Discus requires at least 10 gallons of water, so a 55-gallon tank should have between 5 to 6 Discus for perfect practices.
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How Many Discus Can I Put in A 60-Gallon Tank?

The ideal practice is to put 6 Discus in your 60-gallon tank as a rule of 1 Discus per 10 Gallons with 25% weekly water changes, however, you can put 20-23 adult Discus in a 60-gallon tank if you are ready to change the water twice a week.

How Many Discus Can I Put In A 75-Gallon Tank?

You can put 10 to 12 juveniles in a 75-gallon tank. They can be juveniles bought all at the same time. However, the ideal answer is to have 7 to 8 adult Discus in your 75-gallon tank with a 25% weekly water change.

This stock level would lead to minimal pecking order during feeding, reduce the possibilities of a Discus dominating the rest in the tank and mitigate territorial aggression, and this could cause health issues due to Discus stress.

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How Many Discus Can I Put In A 100-Gallon Tank?

You can put as much as 35 to 40 Discus in a 100-gallon tank if you plan to clean it at least two times a week. If you choose to clean and change your water just once per week, then your aquarium should ideally hold 10 Discus, otherwise, it can lead to casualties.

How Many Discus Are In A 125 Gallon?

You can easily have up to 12 to 14 adult Discus in your 125-gallon tank depending on your filtration system and how regularly you clean up. I would suggest you 25% water change on a weekly basis.

How Many Discus Can I Put In A 150-Gallon Tank?

You can have up to 55 to 60 Discus in your 150-gallon tank if cleaning is done every 3 days periodically. You can put 15 Discus in your 150-gallon tank if you only clean and change 25% of your water once per week.

NOTE: Ideally, the quality of your Discus is dependent on the condition of your tank. More Discus calls for more work, frequent water changes, and cleaning. If you are not ready to go all the way, just stick to the one fish per 10-gallon rule.


As already mentioned, Discus are a bit different to handle as compared to other aquarium fish. They require special care and are to be kept under ideal conditions, a wider tank is always preferable in order for Discus to be happy.

To ensure your aquarium is in its best condition for the proper functioning and growth of your Discus, ensure regular water changes, clean up your tank as often as possible, and always use standard filters to eliminate any toxin from your tank.


This is me Firas Sameer, the founder of, I am an aquarist guy with a passion and love for Discus fishes, I am learning every day with my hobby at home and sharing the things I am learning from my experience with you.

3 thoughts on “How Many Discus Can I Keep in A 55 Or 100- Or 150-Gallon Tank?

  1. Thank you, Firas ! I am desperate for guidance. I now have a 90 gallon with about 10 eba.
    Plus 2 ( 3? ) Ebhaps. The Haps were a surprise delivery. One has appeared only once, briefly. I think I have not imagined that. No problem though. All male. The Acara are all male as well.

    But that aside : I am planning a 225 gallon tank yet to be delivered. I need to confidently stock the tank. Here’s the nagging problem. I want Discus for that tank ( and other fish ) but I am frightened. The fish are costly but most important they are delicate. Can I stock discus without devoting my life to worry and water changes ? I hope you will help me think about all of this. I love Discus but am so afraid.

    I have more I would love to talk with you about, but this is enough for now. I thank you most whole heartedly for any guidance you can offer. Again, I am desperate for a guide and mentor. Best Wishes

  2. Aloha Firas. I live on Kauai and headed back to my second home in the puget sound. I have two new aquariums and stands delivered 250 gal and 200 gal to match my other two aquariums. I plan to house 50 young discuss in one of my older 200+ gal tanks that is heavily planted. The water parameters are fine for discus. All of my tanks are in my game room and the other side is the garage which has all the plumbing for my sump pump systems. i have a timer sprinkler system that runs several times a day moving slow water flow to my aquariums and then funnels the excess water outside the garage. No nitrate levels whatsoever. Indeed the system runs while we are wintering in Kauai with auto feeders and someone checking in daily, this has worked out well for me. Just thought I would say thanks. If you are inclined, I would not mind any advice on where to shop for the 40-50 discuss. I will likely buy them online because I live on another island in the Puget Sound and in assorted batches. I am expecting attrition and when that occurs, I will likely replace with more mature specialty fish so they all same sized. I have little experience with internet vendors on the internet.

  3. I am planning to convert my 125 gallon tank into a solely discus tank. What type of food do they require? I presently have silica sand as the substrate.Can I continue to use silica sand or do I need a different substrate?

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