I'm new.
For Tiger Barbs, some websites say that I need 10-15 gallons of water; other sites say 2-5 Gallons of water needed for a good environment. Which one should I go for?
The question of removing water and adding water:
I currently have this old..old.....OLD REALLY OLD tool which the labels & stuff have worn off. My dad has found this in our old house, used for pumping water out of a fountain or something. I'm not sure if this could do for my small tank, roughly 1/3 of a metre long, 20 cm high and 20 cm width. Would this probably take away my neon tetras and tiger barbs? )