guppies are cool, i have 4 in mine (all male)
i guess any fish you fancy would be good as long as they are compatible!
it's all a matter of personal taste of course.
it's easily treatable with anti white spot from the pet shop, some fish are more susceptible, especially clown loaches, give them a dose and they should be right as rain
as for what causes it, i believe it is a parasite of some sort, tho others may be more accurate than me, i've been keeping...
definitely, i had 4 tanks on the go several years ago, and having now had the 260l i feel the need for another...am fancying axolotls for the other one!
thought i'd come say hi, new to this site but not to fish keeping (have been doing so for approx 20 years now)
currently have 260l tank and trying to resist the urge to get another!
have had numerous tanks/fish over the years but always looking for advice!
current 260l houses: 2 silver sharks...