I'd like to thank DaveC on the DiscusAsAHobby forum for allowing me to use his post on buying discus. It has a lot of useful information in one spot that is helpful for beginners.
Selecting the vendor
Before buying fish from someone do some research on that vendor. Search the forums for that person’s name and read all the feedback that you can. Be aware that much of the negative feedback that you may find can be flawed and one-sided. When argumentative threads are found pay close attention to the response of the vendor as that will tell you more then the attacks on the vendor. Even more attention should be paid to the day-to-day posting of the prospective vendor. If they are only on the forums posting marketing related info then don’t expect much more from them in terms of after sales support. Also consider how long they have been posting on the forums, and how long they have been in business. Some vendors don’t belong to forums at all and this should not be judged as a detriment… some people are too busy selling quality fish to spend time chatting on the net. But there must be some method of communication available and the vendors with the larger then life public image have more to lose from selling you a box of culls. Make yourself known on the forums that these vendors post on so they come to know who you are and have a vested interest in making you satisfied with the fish that you may purchase from them.
Selecting the fish
In every case I would ask to see new pictures of the fish you’re ordering, even if it’s just an overall picture of the tank that the fish are in. This allows you to see the care that they are receiving as well as get an idea of size, shape and health. While it may be unreasonable to choose individual fish from such a photo you can see the characteristics of the fish and choose that way. For instance in a tank of Marlboros you could ask for fish that are solid, no pattern, and deep red. Spell out exactly what you are looking for. Some vendors plead ignorance to defects such as pepper on fish so make sure you detail what you want & what you don’t want. Mind you, if any vendor acts like peppering on fish is a preference rather then a quality issue, I suggest you look elsewhere. If you are buying adults or near adults and you want to breed them then ask for a mix of male/females. It’s not that you’ll get exactly what you asked for but it should prevent you from getting a box of adult fish all with male characteristics. Pictures of the individual fish are the best and if you’re buying adults it could be a demand on your part given the cost of the fish. Do not buy fish that have not yet arrived at the vendor’s location. Wait for them to get there and to be quarantined for at least two weeks and insist on seeing a picture of the fish in the vendor’s tank. A pic of how the fish looked in Asia is meaningless. If you do agree to receive fish without quarantine then realize that you are taking the risk of fish loss and damage.
Discuss the quality of the fish that you expect to receive and that the vendor plans to sell. Every tank of fish will have a few winners, a bunch of high quality fish and some lesser quality fish. How they leave the tank depends on the vendor. Some will sell the best fish first until all are gone and then flog the rest on the LFS or sell them off cheaply on the net. Others will hold the best for themselves as potential breeders or for friends. If you want the best fish in the tank then ask for them and ask what the price will be for the best. Many vendors will sell all fish for the same price but some will charge more for the best in the tank. If you haggle with a vendor to the point where the price if very low you will likely be getting the lower quality fish.
Terms of the deal
Make sure you discuss what happens if shit happens. Ask, in writing, who is on the hook if there are DOAs and expect a response in writing. Do you get a refund or a credit? How long after you receive the fish do you have to contact the vendor? What form of evidence do you need to provide? What if the fish are alive but are severely damaged from shipping? How long will the vendor let you try and nurse the fish back to health before you can both give up & start again with new, healthy fish? Do they guarantee that the fish arrive alive & healthy or just alive & breathing? Too many people are caught up in the concept of buying the fish and don’t want to weird the deal by asking about fish death. These are not the types of questions you should be asking after you receive the fish and have problems. In most cases, after you have received the fish and let the vendor know that they arrived in satisfactory condition the transaction is complete and the risk of caring for the fish is yours.
Method of shipping
The only method I would use is airport to airport. It’s inconvenient depending on the distance to the airport for you or the vendor but it’s the fastest, most dependable method available. But I’m in Canada and most fish that I’ve ordered come from the U.S. so clearing customs in person is the best way to shorten the trip. There are no special documents that are required for receiving fish from the U.S. other then an invoice that details the fish received, the price, date, vendor’s name & address and country of origin. If the vendor fudges the invoice to lower the price you will pay less duty & taxes.
Receiving the fish
I believe in the old grab ‘n plop method of landing fish. If they’re small fish just pour them through a net and put them in the tank. If they’re larger, remove the fish by hand and place it in the tank. I’ve never lost a fish with this method. The water they’re in can be toxic and cold so the quicker they get in good water the better. A rise in temperature or a rise in pH won’t harm them. If your water is very low in pH then a slower method of acclimation is recommended. Prepare your tank by getting the temp up to 88-90ºF. It’s not a bad idea to add 1 TbSp of salt per 10g of water. Leave the fish alone for the first day/night and feed the following day.
When you put large Discus into a tank they will often go to the bottom and lie there for as much as a full day. It’s very common and isn’t usually anything to worry about. But it also points out the need to have your tank very clean and empty other then the newly arrived fish. It wouldn’t be good to have plecos sitting on Discus that are lying on the tank bottom. Small fish may hide behind any filters you have in your tank but usually they are swimming about immediately.
You should have a quarantine tank that is barebottomed, properly heated & filtered with a cycled filter. It should be a reasonable size for the fish it's housing but it needn't be huge. Quarantine your fish for 4 weeks alone and then add a fish from your existing stock to the tank and watch its behavior for another week or two. The best method of buying fish is to buy a tankful of fish at a time (or more) and that way the new fish go into their own tank to stay. But even if you do this you shouldn't mix equipment with tanks of newly arrived fish and other fish.
Winding it up
While feeding the fish for the first time that is the best time to determine the health of the fish and report back to the vendor. I usually let the vendor know if any fish died upon arrival and follow up the next day regarding my satisfaction with the purchase. Detail any concerns that you have at that time. If the fish are alive and eating and the quality is as discussed with the vendor then the terms of your contract should be met and you should let the vendor know that you’re satisfied with the fish. Very few transactions that go sour are ever resolved by publicly trashing the vendor on the net. Be aware that once you do that you are giving up all hopes of resolving the issue. Many still do this to get even with the vendor or to warn others of shoddy practices. That's ok too, but you should know that you won't get money/fish after crapping on the vendor.