Jack Dempsey Cichlids are one of the more popular cichlid species available today. If you’re interested in Jack Dempsey fish or thinking about getting some for your home aquarium, this post will hopefully help, as we answer 25 questions about Jack Dempsey Cichlids and their care.
1. What Is A Jack Dempsey Fish?
A Jack Dempsey fish is a species of cichlid that originates from the Amazon River Basin of South America. These fish tend to grow between four and six inches in the wild; however captive bred jack dempseys are typically much larger than their wild counterparts.
The jack dempsey is a relatively rare species of cichlid that typically inhabits ponds and quiet pools of water. Despite this rarity, jack dempseys tend to stand out due to their large size and striking colors. Jack Dempsey cichlids are known for their coloration which ranges from gray, purple or deep brown. They also have pleasant shiny green blots to gold spots with dark streaks on their backs. Males tend be more colorful than females.

2. How Long is the Jack Dempsey Cichlid Lifespan?
Mature jack dempsey fish typically live about ten to fifteen years, but certain specimens have been known to live as long as twenty-five years old. They are well known for their hardy nature and relatively easy care requirements; however jack dempseys can be very aggressive towards other tankmates.
3. What is the Jack Dempsey Cichlid Max Size?
In the wild Jack Dempseys tend to grow to a maximum of about six inches, in captivity however they can grow up to eight, maybe even as much as ten inches! Jack Dempseys require a lot of space!
4. What is the Best Jack Dempsey Cichlid Tank Size?
I would say for a single Jack Dempsey you would need to have a tank of at least 55 gallons. If you are thinking of keeping a pair of Jack Dempseys you’d need at least a 100 gallon tank!
The jack dempsey requires a large tank with plenty of places to hide and swim. A jack dempsey cichlid is not a fish that will feel comfortable in a ten gallon tank for very long, you want to be sure to have as large as possible aquarium for this fish.
5. Can You Keep a Jack Dempsey Cichlid in a 20 Gallon Tank?
No, a jack dempsey will need at least a 55 gallon tank to themselves if not even larger. They are quite big fish and require a lot of space. They will not do well in a tank smaller than 55 gallons.
6. Can You Keep a Jack Dempsey Alone?
Yes you can keep a jack dempsey by itself, however I would highly recommend that if you do plan to keep this fish alone that you give it an extremely large tank. The larger the tank the better as jack dempseys are very active and will need lots of room to swim if they are kept alone.

7. Can 2 Jack Dempseys Live Together?
It is advisable not to keep more than one Jack Dempsey in a tank, unless you are a very experienced fishkeeper. Certainly, 2 male Jack Dempseys should not be kept together as they would be extremely aggressive towards each other.
8. Can You Put a Jack Dempsey in a Community Tank?
You can keep jack dempseys in a community tank, just be extremely careful when you are choosing fish to go in with them. They are known for being aggressive and should certainly not be kept with smaller or more passive fish.
9. Do Jack Dempseys Eat Other Fish?
Yes, it is possible that a Jack Dempsey fish would eat smaller fish in the aquarium. In the wild the diet of a Jack Dempsey would include small fish along with crustaceans, worms, insects – anything meaty that they can fit in their mouths really!
10. Are Jack Dempsey Fish Aggressive?
Yes, jack dempseys are known for being very aggressive and territorial. It is very important to be careful when choosing tank mates.
11. Why Are Jack Dempsey Cichlids Aggressive?
Jack Dempsey cichlids are aggressive due to the fact that they are extremely territorial. They do not have any qualms about attacking other fish in their territory. In the wild their survival depends on their territory providing them with enough food, breeding areas and hiding places and so they can’t afford to share the space with other fish and compete for these resources – these instincts remain in the aquarium.

12. How Do Jack Dempsey Fish Fight?
Jack Dempsey fish fight by biting and ramming each other, as well as flashing their fins. The heavier jack dempsey will normally win the fight due to its weight advantage. The jack dempsey tank should certainly not be overcrowded as this will only lead to more aggression particularly during feeding times.
13. How To Stop Jack Dempsey Fish Being Aggressive?
Providing your Jack Dempsey fish with a larger tank, plenty of hiding places and enough space may help reduce their aggression. Also, think very carefully before deciding to add new fish to your aquarium – Jack Dempsey fish can be very territorial and may see any new tank mates as a threat and become very aggressive towards them.
14. What Fish Can Live With Jack Dempsey Cichlids?
In a large tank you could potentially house jack dempsey cichlids with larger, more dominant fish such as Oscars or other Cichlids and also some bottom dwelling catfish like the Common Pleco make good tank mates for the Jack Dempsey fish as they occupy different areas of the tank.
As jack dempseys are quite aggressive great care needs to be taken when selecting fish that can live with them. In a community tank jack dempseys should certainly not be housed with smaller or passive fish.
15. What Should I Feed My Jack Dempsey Cichlid?
Jack dempseys are omnivorous meaning they will eat both meaty foods and vegatable based foods. They will eat live insects, worms, crustaceans and any meaty foods they can fit in their mouth, but they can also be given vegetable based foods such as spinach or lettuce to make sure that all of their nutritional needs are met.
The easiest way to make sure your Jack Dempsey gets all the nutrients it requires is to provide it with a good quality flake or pellet fish food and also the occasional treat of frozen or dried bloodworms, daphnia or brine shrimp
16. How Often Should I Feed My Jack Dempsey Fish?
In the wild jack dempseys will eat whenever food floats into their territory, but in an aquarium they can be fed once or twice a day. Ideally feed your jack dempsey cichlid small amounts of food several times a day as opposed to large amounts just once a day. When you feed them, make sure to provide only enough for them to consume it all within a couple of minutes as excess food can cause the water quality to deteriorate.

17. What Type of Water Does A Jack Dempsey Fish Need?
Jack Dempsey fish need water with some acidity to it, something around 6-7 on the pH scale would be great! You can tell how acidic or alkaline your water is by using an aquarium water test kit.
Jack Dempsey fish also require water hardness in the range of 9-20dGH and water temperature somewhere between 72-86F (22-30C)
18. What Is The Best Substrate for Jack Dempsey Cichlids?
Sand or gravel both work well as substrates for jack dempsey cichlids, however if you are new to jack dempsey fish keeping then gravel is probably the easier of the two to start with.
19. How Hardy Are Jack Dempsey Fish?
Jack dempseys are actually one of the hardier species of cichlid available to fishkeepers. They can withstand a range of water conditions and temperatures are not picky eaters and can live for over a decade when they are in a stable, thriving aquarium with minimum maintenance.
20. Do Jack Dempseys Change Color?
The jack dempsey fish might change its coloring to be slightly brighter or darker depending on whether or not it is happy or upset, but it doesn’t make dramatic and obvious changes. The jack dempsey fish won’t change color to make itself more attractive to the opposite sex as some animals do.
If you notice that your Jack Dempsey’s is suddenly paler than normal it could be a sign of stress or of illness so you should monitor it closely and take appropriate action.
21. Are Jack Dempsey Cichlids Nocturnal?
The jack dempsey cichlid is not nocturnal and will be awake during the day if it is happy with its living conditions. You may find that your Jack Dempsey is more active when it’s darker – this because in the wild dawn and dusk are better to times to find food like insects to eat.

22. Are Jack Dempsey Cichlids Mouth Brooders?
No, Jack dempsey cichlids are not mouth brooders. Mouth brooding is when the female keeps her eggs in her mouth to incubate them [source]. African Cichlids are mouth brooders, however Jack Dempseys are not.
23. Can You Keep A Jack Dempsey Cichlid With Angelfish?
No, it is not recommended to keep a Jack Dempsey cichlid with angelfish. A mature jack dempsey cichlid will likely be very aggressive towards angelfish.
An experienced fishkeeper with a very large tank, that provides plenty of space for the angels and the Jack Dempsey may be able to successfully house them together but for most people it’s not a good idea to try and keep them together. If you are interested in Angelfish – check out this article about stopping Angelfish bullying behavior!
24. Can You Keep A Jack Dempsey Cichlid With African Cichlids?
No, it is not advisable to keep jack dempsey cichlids with African Cichlids as they are both very aggressive and will more than likely fight.
Jack Dempseys are larger than African Cichlids and will probably bully the smaller species which can cause it a great deal of stress and may eventually cause it to die.
Even if you happened to have a particular calm and docile Jack Dempsey, it would probably still be a bad idea to put it in with African Cichlids as they, despite being smaller, would take advantage of the jack dempsey cichlid’s docile nature and attack and harass it!
25. Can Plecos Live With Jack Dempsey Fish?
Generally speaking a Common Pleco would make a good tank mate for a Jack Dempsey fish.
Jack Dempsey fish can get pretty big which, when coupled with its aggressive nature, can be very threatening to other fish. The Common Pleco however, is not really affected by this as it gets pretty large itself – they can grow to be over a foot long!
Common Plecos tend to keep to themselves whilst hoovering up algae and other food debris from the bottom of the tank, they don’t tend to get in the way of Jack Dempseys so are normally left alone. Even if they were to receive a bit of attention from a Jack Dempsey they are big and strong enough to withstand a little nip every so often.

Summary – Jack Dempsey Cichlid Care
In this article, we have been discussing jack dempsey cichlids and answering some common questions about them. The Jack Dempsey is a wonderful fish, it can tolerate a range of temperatures but does require a large tank and you do need to be careful with what other fish you choose to keep with it.
I hope you enjoyed the article and found it useful!