Keeping discus at temperature lower than 27 degree will be asking for trouble.
You don't need oceans, lakes or rivers to keep fish.
How you maintain them is the key to keeping happy healthy fish.
I have 6 wild discus, 5 clown loach, 3 striata loach, 1 flying fox, about 19 different bristlenose and 4 harlequin all living and growing happily in a 245 ltrs tank. They are all decent size fish too.
Ron
You won't be able to get the shrimps in nz like Cam mentioned.
Bristlenose sucker fish will be fine but a common pleco will grow too big for the tank.
Stocking the fish depends on the type of filtration you have in the tank and how well you maintain it too.
Ron
I would start by doing a 50% water change and filling the tank back up with warm dechlorinated water.
How did you do the fishless cycle and did you do a big water change after cycling before you introduce fish.
It pay to put your location in your profile so people know where you are.
Salt bath don't actually help. It's mainly for dislodging parasite on the fish body.
30 mins is way too long. If the salt solution is strong they should turn over within one minute.
I wouldn't do it more than 2 minute.
Put epsom salt in your tank.
:gopo: :iag:
It all come down to how you maintain your tank.
How often do you see 30+ cm clown loach. They take years to grow that big.
As for the goldfish you can half fill a 20 ltrs bucket and put it in. Slowly add water from the cold water into it. Then release it into the tank.
Ron