Fin Rot or Fin Loss?

[Keels]

Don't add guppies to a tank containing a male Betta splendens. They require different water chemistry (Bettas have soft acid water, guppies have hard alkaline water), and the Betta could attack and kill the guppies.

Dirty tanks don't make any difference to hydra. They come in on plants and ornaments and divide and spread through the tank. You can have a really clean tank or a filthy tank and they can both have hydra.

Do you think I would have a better chance with something like neon tetras? or would you avoid adding fish all together?

my LFS also mentioned the posibility of panda corys, but from what I understand they need sand substrate.

 

[Salty&Onion]

Neon tetras need soft water and a 30 gallon tank, 90cm long (36") and yes, cories need a sand substrate and a 20 gallon tank and a group of six or more.