I would not buy these on a whim, careful research is needed to keep this little fish happy and healthy!
I did a lot of researching on keeping these guys and finally set up a tank for them. They need special care, I'm using melted snow/ rain water with botanicals to get the pH below 6. It's only been a few days since I've gotten them acclimated but they are doing surprisingly well! At first one of the small ones had a droopy back end, the next morning it is perfectly fine. One of the medium sized fish has a scrape/bump on it's head but behaviors normal like the other 5. They are happily eating their live food and even pecking at dried foods. So far the group likes to stick together, looks like 2 big males and 4 young ones/females. I got to see one of the males displaying to the other, very cool to watch!
Not entirely sure these are P. deissneri but their care should be the about the same regardless. Hopefully they'll be happy enough to spawn for me and become less shy with time. They are my very first blackwater species but I think I can care for them pretty well despite being a novice with soft water fish.