Yes, Martha is is a Juwel Rio 240 (60usg) at the moment with an upgrade to her final 125usg tank within the next few months.
To my knowledge, we've never had an internal parasite problem.
The best way to fight any disease is with good food & clean water, then even if the fish does have an infection it will be kept at bay by a healthy immune system.
Puffers are very tollerant to salt, even the freshwater species as long as it's only short term, so adding a little salt may help.
Do not add salt if you have plec tankmates like we have.
Adding commercial medication such as Interpet No9 is also safe as long as the dose is reduced.