Discus fish is not eating


New Member
Mar 26, 2019
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Hello Dears,
i would like to get Help from you guys as i'm not totally beginner in this hobby but new to discus fish keeping, now i'll throw some info about my tank
it is a 125G planted tank with a nitrogen cycle up and running from 5-6 months. with some angel fish and platy and tetras in it with canister filter sunsun 404B and a normal sponge filter
- now i'll tell what mistakes i have made
- i bought the first couple discus fish 4 days ago
- then i bought the second couple 2 days ago
- and yesterday the last couple so i have now 6 juvenile in total
- i didn't buy all of them at once because i thought 2 is enough then 4 is enough and when i watched YouTube videos almost all of them recommended that they should be group of 6 minimum
- and that made my fishes stress out and hide
- another thing they recommended the tank should be just for discus so i stressed them once again when i tried to move things around while i'm taking out the other angel fishes and tetras....etc
- one of them is dominant and won't let the others eat properly and i'm afraid that it would ruin my water parameters if i try to put more food in it for the other fishes

please help me out

here is a video link so you can see the aggression behavior
* thanks in advance*


Jan 26, 2008
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Perth, WA
When you introduce discus or any new cichlid into an established tank with other cichlids, you should rearrange the tank just before adding the new fish. This breaks up established territories and gives the new fish more chance of finding a territory instead of being put into another fish's territory and getting attacked because it's an intruder.

There are 2 fish in the tank that are dominating the others, both are orange. The one on the far left has claimed the left half of the tank, and the orange discus in the middle has claimed the other half and is forcing the weaker fish into the far right.

If the fish are arguing, rearrange the tank to break up the territories.

Discus need to be kept with other fishes and in a brightly lit room where lots of people move around the tank. This stops the fish becoming shy and nervous and they will settle down better and stress less when people enter the room.

Having other fishes in the tank will give the discus something to chase instead of each other. And if some discus are being picked on, this can reduce the stress on them because the aggression is spread out over more fish instead of just a couple of other discus.

The main drawback to keeping discus with other fishes is finding suitable tank mates that can tolerate the high temperatures. Some tetras are fine in warm water and others die of old age much sooner than they should. Angelfish are fine with discus.

The water temperature for discus should be around 27-28C (81-82F). If the fish get sick you increase the temperature to 30-32C (86-90F). However, you need to have lots of aeration/ surface turbulence at high temperatures because warm water holds less oxygen than cool water.

You also need to do big water changes and gravel cleaning, and clean the filter regularly to keep the number of disease organisms low. I recommend doing a 75% water change and gravel cleaning the substrate once a week. Make sure any new water is free of chlorine before it's added to the tank.

Clean the filter at least once a month and every 2 weeks is better. Wash filter media/ materials in a bucket of tank water.

You need to rearrange the tank and add some more fish to help with the territorial issues.

You can feed the fish individually so they all get fed well and there won't be any wasted food sinking to the bottom. If some food does sink to the bottom, use a net or gravel clean to remove it after feeding.