Discus in a high tech planted tank

[tubamanandy]

Both wild discus, very healthy, up at very top of tank when the lights are off mid morning as if they are gasping for air yet dissolved oxygen reading is 7.9 as usual.

Looks like oxygen starvation but none of other fish loaches/neons seem to be affected. The bars are also quite prominent. When lights are on, no issues and fish all look great !

Any ideas ?

Fully planted and mature hi-tech CO2 tank with lots of plants and light. Nitrite=Nil, NO3=40ppm etc

 

[dw1305]

Hi all,

dissolved oxygen reading is 7.9

I wouldn't rely on this dissolved O2 is difficult to measure even with very expensive kit.

Both wild discus, very healthy, up at very top of tank when the lights are off mid morning as if they are gasping for air

They are, they are a much more accurate monitor than the oxygen test kit, although it is probably a CO2 issue. I assume the CO2 is still on, although the lights are off?The drop checker should give you an idea of the CO2 concentration when this happens.

When lights are on, no issues and fish all look great !

You also need to look at this on the (Bohr) Root effect < Fish Respiration>.

In planted tank the plants themselves are both removing ammonia and CO2 from the water column, and adding oxygen via photosynthesis, and at the end of the photo-period the water is likely to be 100% saturated with oxygen. Once the lights are off photosynthesis stops, the situation changes and the plants become net producers of CO2 and consumers of oxygen. This is why it is safest to turn off the CO2 at night (or any other times out side of the photo-period). Have a look at this thread <Overnight CO2 | UK Aquatic Plant Society>.

cheers Darrel

 

[Achintya]

Discus in a planted aquarium:

Without any doubt, planted tank is one the beautiful looking of any kind of tanks. Many of us love to keep planted tank. It’s nice to see some awesome planted aquarium. It’s a great feelings when one keep beautiful discus in a planted tank. Especially when we see beautiful planted tank with discus we are amazed to see this beauty. Let me assume that you also keep planted tank. Now for the first time you want to keep discus in your planted. Ok, don’t worry. You can keep discus if you know some tricks about them.


i) Different types of discus that you can keep in a planted tank:

You have to be choosy enough for different strain of discus in a planted tank. You can’t choose all types of discus in a planted tank. Let me assume that you have a beautiful planted set up. But you keep some peepering prone or such type of discus. I see many planted experts keeping discus in their tanks but they keep juvenile and peepering discus. I feel very sad to see this. So to avoid this you can keep all turquoise strain, leopard, snakeskin, san merah, blue diamond etc.

Other type of set up is high-tech planted tank with pressurized CO2 system, branded substrate, high light, proper dosing etc. keeping discus in this type of set up is little tricky. A branded substrate can cause problem for discus. In addition, due to high light, dosing, CO2 your discus can be stressed. So to avoid this what’s the option? The only option is to keep adult discus settling in this type of environment. I know many planted discus keepers who keep adult discus in a temporary planted set up and if a discus is settled enough then only they can transfer that discus to the main planted tank. But in your case I like to say that keep 4-4.5 inch+ (at least) discus. As you know adult discus is having more resistance power, so it will not be too much problem. Also one thing that I like to suggest you, In case of hi-tech planted set up please keep discus once tank is fully matured. During set up time there can be some fluctuation of water parameters which is hazardous to discus. You may say that in many cases I see lots of other strain of discus housing in a hi-tech planted tank. In most of the cases those discus are kept in this set up for a better video or picture purpose.



ii) Fish size you’ll choose for this type of tank:
Keeping discus in a planted aquarium is not like keeping discus in other types of tank. In other type of tanks you can easily keep and successfully raise 2-.25 inch discus. But for planted tank I suggest you to keep adult discus. As we all know adult discus can adapt more than juveniles. So keeping 4 inch plus discus is a very option for a planted tank. Since you use pressurised CO2 (for high-tech set up), we’ll often find juveniles are stressed or often goes top level of water. Discus demands more oxygen and in case of juveniles they need more than adult. That’s one of the reasons to choose adult discus in a planted tank.Also you know that discus will live better in a group. So keeping a batch of 4 inch size discus will be no problem for you.​

 

[ceg4048]

Hello,
There are no tricks necessary to keep discus in planted tanks, and there certainly are no requirements to choose a specific strain. In fact, the larger the fish the more susceptible to CO2 toxicity the fish is. Therefore, theoretically juveniles have an easier time than adults would. I've kept infants and juveniles in planted tanks without any issues whatsoever. Discus are not particularly stressed by any other parameter except for CO2. Again, this is true of any fish.

I completely agree that fish should not be added until the tank has matured, however, this is true for any fish, not just discus.

Follow the general rules for keeping discus, such as large and frequent water changes, feeding quality live food, and keeping the temperature elevated and this will be completely consistent with the requirements of a high light CO2 injected tank.

The only real reason people freak out about discus in a high tech tank is because if you gas your fish you will be out a lot of money. It's much easier to swallow gassing a few tetras, which cost a dime a dozen comparatively speaking.

Also, CO2 addition increases the Oxygen content of the water by way of photosynthesis, which is an Oxygen producing chain of reactions. CO2 in no way competes with Oxygen, therefore one need not worry that CO2 displaces Oxygen in the water column.

Cheers,

 

[dw1305]

Hi all,

In fact, the larger the fish the more susceptible to CO2 toxicity the fish is. Therefore, theoretically juveniles have an easier time than adults would.

Clive is right, gill area increases as a square (power 2), whilst body volume increases as a cube (power 3). If we have a fish that has a similar morphology as both juvenile and adult, the juvenile has a proportionally much larger gill area for gas exchange. This is why large fish are always the first to die during low oxygen (or high CO2) incidents.

Some cichlid actually use this as a strategy for rearing their fry, where the fry are left in warm shallow "thermal refuges" where high temperatures mean that the DO levels are too low for larger fish to enter.

The only real reason people freak out about discus in a high tech tank is because if you gas your fish....

I'm a non CO2 user for this reason.

.....you will be out a lot of money. It's much easier to swallow gassing a few tetras, which cost a dime a dozen comparatively speaking.

I'm pretty careful with my money, but personally I don't feel that the value of the fish is the relevant factor in this issue.

cheers Darrel