Discus fish getting very weak

Question
Hi, I asked a question a few days ago about a discus fish that was not eating.
Once the fish was quarantined, he/she started to take interest in the food but over that last day has become very week and no longer takes interest when i put food in the tank. I have been holding it in front of his/her mouth and he/she would peck at it and take some. I have only tried a few foods so far(flake food and blood worm). He/she spat out the blood worm so we reckon that he/she is not accustomed to meat so we are just going to test various different veg.
I want to know what to do next and if i have to do drastic things such as forcing food down his/her throat.
I have been cleaning the tank out every two days, but only small water changes, and also hoovering up the food he/she didn't eat.
The discus usually eats blood worm, flake food, brine shrimp, spinach, courgette and algae waffers.
Thanks

Answer
AJ,

Discus are probably one of the hardest, if not THE hardest fish to keep. I found this information online. I hope it helps.

Here is a guide to keeping discus:

1. Discus need crystal clear, clean water. Weekly partial water changes will be necessary. We recommend pure R/O water with deionization.

2. Keep the pH around 6.5.

3. Temperature around 84. Breeding Discus should be kept at 88 degrees.

4. Softwater is needed. We recommend Blackwater Extract.

5. Plants, especially sword plants, do nicely with Discus. Just remember to clean the gravel frequently. Plants act as a natural filter to enhance the water quality.

6. Discus need lots of oxygen, so keep an outside filter and an inside sponge filter for extra aeration. We also highly recommend a UV sterilizer. Ideally, we recommend 1-micron filtration. Discus are extremely susceptible to external bacterial infections, so UV Filtration and special filtration are very important.

7. We highly recommend keeping at least one Plecostomus catfish in the aquarium. Some species of Plecostomus harass Discus, so we only sell Plecos on our website that are safe with Discus.

8. Gouramis, Corydoras Catfish, and Angels are also compatible tank mates for Discus, but you have to be a little careful with the Angels, because they can be carriers of Discus Plague.

9. Do not keep Discus with aggressive fish, which includes most Cichlid Species, or with fin-nipping species such as many Barbs and Tetras.

10. Discus are grazers, so feed them several times a day with a food that slowly sinks to the bottom. We recommend feeding Discus three times a day. If that is impossible, feed them at least twice a day with as much as they can eat in 10 minutes.

11. We feed our Discus the following foods.
(a) Freeze Dried Blood Worms.
(b) Sterilized Frozen Blood Worms frozen to -60 F. to kill Hexamita.
(c) Glass Worms are high in fat content and the best food for Discus.
(d) Frozen Brine Shrimp fortified with Spirulina Algae, because Discus require some plant material. We do not feed our Discus Beef Heart, because it ends to quickly foul the water. We supplement our food with vitamins and minerals.

12. Many Discus do not show their full colors as juveniles and will not until they are mature adults.

13. Gallons per inch of Discus: 2-gallons for each 2" Discus, 3.25-gallons for 3", 5 for 4", 7.25 for 5", 9 for 6". Do not crowd Discus beyond these guidelines. So six 2" Discus will require at least 6 x 2-gallons = 12-gallons of water, and when grown to 6" they will require at least 6 x 9-gallons = 54-gallons. A bigger aquarium is always better.

Guide courtesy of somethingsphishy.com