Care and Feeding

Frequently Asked Questions

What temperature should I keep my discus at?  Discus do best at 82 to 86 deg F.  We keep our discus at 84 deg F.  When you change your water, make sure the water you are adding to the tank is a degree or so warmer than the water already in the tank.

How often should I change the water, and how much should I change? We recommend changing your water twice a week.  Your should gravel vac the substrate, wipe down the tank, and change at least 50% of the water.  If you have more than the recommended number of discus in your tank, you should change your water more often.

How many discus can I have in my tank?   Regarding the number of discus for your tank, the general rule is 10 gal per adult discus.  A 215 gallon tank can easily accommodate 21 or 22 discus. A 55 gallon tank can accommodate 5 or 6 discus.  I would not go with more unless you plan to change the water more than several times a week, which may be difficult with a large tank.

Can I get just one discus?  How many do you recommend getting for my tank? Discus are schooling fish, and thrive in larger groups.  If you are new to discus I would recommend starting out with a school of at least 3-5 discus that are 5″ or larger.    You can add more over time, but I would recommend adding them in groups.  Also, many people like to get one of each variety.  I suggest that you get two of each variety.  They will hang out together and it will be less stressful on the fish.

I have read that discus like low pH.  What pH do you recommend?  Discus are very adaptable to a wide range of pH from below 6 to over 8.  While it is recommended that the pH be lower (6.0-6.5) for breeding, it is not necessary to keep them such a low pH.  They will do just fine at the pH of most tapwater.  The trick is to keep the pH consistent.

What is aging the water all about?  Sometimes the water coming out of the tap is a different pH that the water that has been sitting overnight in the tank.  For example, our water comes out of the tap at 6.8, but after a few hours it is 7.6 or higher due to degassing of dissolved CO2.  For this reason it is recommended to age your water until the pH stabilizes, and then use it for changing the water in the tank.  Aging also eliminates microbubbles.  Remember, you don’t want big pH fluctuations in the tank.

How about R/O (reverse osmosis) for water?  Unless you plan on breeding RO water is not necessary.  They do fine in tapwater.  The only exception would be if you have rock-hard well water, i.e. with hardness values up in the high teens or 20s (tds 450 or more).  Then you might want to mix RO water with your tapwater to get the hardness down to 9 or 10 (tds 250 or less).

Are bare-bottom tanks necessary?  Regarding bare bottom tanks, a bare bottom is fine.  But if you have a bare bottom, I do recommend painting the bottom of the tank (on the outside) to eliminate reflection.  Discus do not like to see fish coming up at them from below, and their reflection on the bottom stresses them.  There is no reason to keep a bare bottom other than ease of cleaning.  I suggest you get a light colored rounded gravel, or heavy flint sand, for the substrate.  It looks better and the discus like it.

Can I add decorations to my tank? Of course!  Discus like to interact with their environment and have places to hide.  Driftwood is fine but be sure that it does not have any sharp edges or branches.  Smooth manzanita driftwood is best.  A planted tank is fine as well.  A planted tank requires a lot of maintenance, but it does look beautiful.  If you are into a more low-maintenence tank, try artificial plants.

What color should I make the background of my tank?  Many of our customers have tanks with dark backgrounds.  Discus do try to mimic the background.  For example, Blue discus (Cobalt, Diamond, Snakeskin, etc.) will turn a more intense blue with a darker background.  This is natural and they are very attractive.  Pigeon Blood discus (Checkerboards, Melons, etc.) however may tend to “pepper” with a dark background.  They lack the mechanism to darken all over, so they do it in little pepper spots.  This doesn’t happen all the time, but it is a real possibility.  We recommend a light blue or similar light colored background. If you cannot change to a lighter background, you can compensate with a light colored substrate and decorations.

Should I quarantine my fish before adding them to the tank?   Yes.  There is an excellent Guide written by Paul Villenueve on the Simply Discus Forum.  Paul has been keeping fish for over 50 years, and I have tremendous respect for his knowledge and guidance.  In this guide he discusses the reason for quarantine.  I am quoting him below.  Please refer to his guide for specifics on how to quarantine, and for many other tips on successful discus keeping.

 “You need to do this as the new fish may be harboring pathogens they are immune to, but the existing fish are not. Also, the stress of the move may cause problems for the new fish, and you don’t want to transfer this to the existing tank. Finally, if the existing discus harbor pathogens they are resistant to, but the new fish are not, then one risks the potential loss of some new fish. Therefore, all new fish, whether purchased from the same source or not, should be quarantined.”


For those of you that purchase Discus from Chicago Discus online this is how we recommend you acclimate your new Discus. Before receiving your new fish test your tanks pH and see what you are working with.

1. Float the bags in your tank for 15-20 minutes to adjust the temperature in the bag to the temperature of you tank.  You don’t want to subject your fish to thermal shock.

2. If the pH is lower than 7.0 or you are using R/O water then you will need to take some precautions when acclimating. Take normal airline tubing with a shut off valve attached that can reach from the tank to your bucket. Get a five gallon bucket and place the bucket below the tank on the floor. Cut the bag open and gently pour your fish and water into the bucket. Take a couple cups of tank water and pour it into the bucket as to neutralize the shipping water. Then start a consistent drip (not a flow) into the bucket. When the water reaches the top of the bucket you are done. Net the fish out and place him in your tank.  The entire process should take less than 1 hour.

3. If the pH is higher than 7.0 and below 8.3 than just place the unopened bag in the tank and wait 20 minutes. Cut the bag open dump the shipping water out and slide the fish (not the shipping water) in the tank.

4. Once you have safely placed your fish in the tank, turn the lights off for the remainder of the day and let them get use to their new environment. The next morning turn the lights on and start your normal routine.

This video shows Josie acclimating Frank’s Giant Floras in a tank with pH that is over 7.0.


The question we are asked most often is “What do you feed your discus and how often do you feed them”.  Discus like a varied diet that contains high quality nutrients, but they like their goodies as well.  We feed adults at least twice a day, and juveniles at least 3 times a day.

Sera Discus GranulesIn the morning, Beefheart Mix according to our own recipe (see video and recipe below)

In the afternoon, Sera Discus Granules and/or Freeze Dried Australian Blackworms

In the evening, Hikari Frozen Bloodworms and Hikari Frozen Brine Shrimp

Discus are slow eaters, sometimes taking an hour or more to finish a meal.  But be sure to remove all uneaten food so it doesn’t foul the tank.  However, you can leave the bloodworms and brine shrimp overnight and clean up uneaten bits in the morning.  Your discus like to snack at night.  You can buy Sera Discus Granules, or other special discus granules, and Hikari Frozen Bloodworms/Brine Shrimp from your local aquarium or pet store.

Basic Beefheart Recipe

Here’s the basic beefheart mix recipe that we use.  You can adjust the quantities according to your needs, and feel free to add other ingredients that your discus may like.   Frozen Cyclopeeze as seen in the video is no longer available.

10 lb trimmed beef heart
1 lb salmon (skin off)
1 lb shelled jumbo shrimp
3/4 lb cooked spinach
1 large ripe banana
2 vitamin/mineral tablets (ground)
2 fish oil capsules (1000 mg, cut open)
2-3 tbsp ground garlic
1/2 cup spirulina flake (binder)
1/2 cup high quality flake food (binder)

Grind the first 5 ingredients together using a meat grinder or food processor.
Mix the remaining ingredients into the ground meat mixture using food processor (low speed).
Pack 1.0-1.5 lb in flat sheets in 1 gallon ziplock bags.
Freeze until ready to use.

When feeding your frozen beefheart mix, be sure to chop or mince it up into bite size kibble pieces.  Discus do not like to eat from a chunk they cannot get in their mouth.  

 Making Beef Heart