I also just started a planted tank with discus not long ago in Feb 2017. I read through Paul's advice - great stuff!
Thought I share with you a few points from a fellow newbie's perspective when starting a discus tank with plants.
1. Experience with planted tanks/hi-tech tanks. I have had planted tanks with CO2 for 10 years but never had discus. Planted tanks with CO2 increases the level of difficulty of maintaining a healthy tank for discus. It is possible to increase the safety factor if you are still going down that path but the path will take longer. For example, I started my discus tank with plants way back in Jun 2016 but I did not add in the discus until Feb 2017. The reason for this is for me to get the right balance of lighting, CO2 and fert regime for healthy plants with minimal algae. If you are inexperience with hi-tech setup, the potential of suffering from BBA infestation is very high and that will ruin your plants. (although it has been shown that BBA will also infest low-tech planted tanks for those who are inexperience.) The key point here is - don't introduce too many variables at the same time if you want to have discus.
2. In my current tank (
http://forum.simplydiscus.com/showth...=1#post1255994), I have gone through a deworming regime for my 10 discus. As part of that regime, I have added salt for 48hours to help them adjust. Salt will cause plants to dehydrate as the plants will lose water through osmosis. Plants like crypts and duckweeds did not take the salt very well and they wilted. Plants like amazon swords, anbuias, jungle vals and ferns were not affected. I dose salt at 2 gram per litre. The key point here is - at one point in time, you will need to treat the entire tank for either fluke infestation or fungi etc... you will need to select hardier plants or just be prepared to lose some plants.
3. Put in the discus last. Think of it this way, the plants and the tankmates for discus are being quarantined in your main tank. You want to make sure that these are treated to your best of your ability and dewormed before introducing the discus.
4. Think of planted tank as a tank with planted layout. For example, 80% of my plants are anbuias and ferns that are tied to wood and coconut husks that can be shifted easily without disturbing the substrate (I use inert sand). This allows me to do maintenance work (siphoning the sand for waste etc) and also inspect to crevices for BBA. The key point here is to make sure that you have a planted layout that makes it easy for you to carry out maintenance so that you can maintain pristine water quality for the discus.
5. Sump tank. In the planted tank communities, many of them are of the view that sump tanks will lead to a loss in CO2 for hi-tech setup. In my humble opinion, this is a fine balance between healthy plants and management of wastage. Healthy plants will help to improve water quality (by reducing nitrates) but on the other hand, unhealthy plants will only worse water quality by contributing waste organics through dead/decaying plant matter. But for me a sump tank increases the safety margin for you due to a larger volume of water and contains BB that helps remove ammonia and nitrites. But there are some cons you have to take note of. Beside higher loss of CO2, one would also need to take care of medication regime that could wipe out the BB in the sump. If that happens, then you have to be prepared to do daily water changes until the BB establishes themselves back into the media. I like sump over canisters because I use beefheart which in turns create more organic waste. A sump tank allows me to change out the filter wool more easily than a canister and reduces the organic waste in the water.
6. Use of duck weeds or similar floating plants. I like them because they absorb nitrates readily from the water through their roots and they also provide shade from the overhead lights. They also provide a source of food for the discus.... because my discus loves to nibble at them.
7. Quarantine. This will save you heartache. Even plants need to be quarantine. They should be soaked in either hydrogen peroxide or potassium permangate to minimise fungi/algae spores.
Hope this helps!