Should I euthanize

I usually place the fish in a container of water and place it in the freezer..

the fish's metabolism slowly slows down and they die peacefully..

others may disagree, but this is what I feel is the best, most humane method...

sorry about your fish..

I've done what 12 Volt Man suggests.

I'm sorry to hear about your fish. I had something similar happen a year ago and am just now thinking of setting that tank up again.

clover oil is good, if you go into the chat room, everybody is more than happy to talk about using clover oil

I have used clove oil and volka

I would either use clove oil or put the fish in ice water.

Very sorry to hear about your situation. I had to euthanize my Green Terror last week after about a week of watching him slowly get worse. I tried changing his diet first, but then he refused to eat. A day later I went back to the fish store and tried some medication for a couple of days, but it was too late. He was verily kicking by the end and the Texas Cichlid was starting to pick at him. I just took him out (with my hand since he was stuck behind a rock) and let him expire on a paper towell. It only took about a half minute and he didn't struggle. It was very frustrating since he was one of my favorite fish and I'm not exactly sure what happened. The rest of my fish are doing fine. I can't imagine how irritating it has to be to have something wipe out your tank.

So sorry about your issues. I don't have advice to offer on whether you should euthanize, but if that is the road you choose to take, I'd do it one of 2 ways.
1- Clove oil and vodka. Add the clove oil until the fish "go to sleep". Then add the vodka, until... you know. This is generally thought of by many people as the most humane way other than a quick decapitation.. which I could never bring myself to do.
2- Put a cup of tank water in the freezer, until it gets a crust of ice on the top. Break the crust of ice, and put the fish in. Put the cup in the freezer until the ice is frozen (i.e. the fish is gone). This is supposed to work better for small fish like tetras and the like, just to warn you.

If you can get a hold of some clove oil, I would think that method would be better given that discus are not small fish.

Again, sorry for your loss.

i think discus would be large enough that the very very cold water method wouldn't work quickly enough to be painless.

however horrible and traumatic it will be for *you*, i think the fastest way for these larger-sized fish would be to wrap them in something and chop their heads off. take them out of the tank, wrap them up, take them outside, and do the deed. 30 seconds max out of the water, most of the time wrapped in wet newspaper or something else dark. otherwise we're talking a gallon of vodka, a whole bottle of clove oil, and hoping the fish don't jump out. if you do go the chemical route, don't put water in there - straight alcohol and oil. otherwise the oil floats on top and you have to actually stir for a while before the fish comes into contact with enough oil to affect it - tried this method on a severely dropsyed guppy with bad results. apparently the alcohol mixes better with the oil, and both things work to numb the fish to death.