Alright, that's good about the filter! Thanks for the advice. I will find some sort of calcium source. Do you know of any cold water fish that can be kept alone in that tank?
Half gallon is pretty small, and I'd only use something that small as a very temporary home for a betta. Would be great to keep some live plants and snails or a few shrimp in, but "cold water" fish get waaaaay too big.
Alright. I would have a tropical tank but I'm not satisfied with my mini heater. All the heater knows is:
" Add five degrees " And that resulted of a baby molly that died of being overheated. Do you know of any Mini heater that has a built-in thermostat?
I've read a lot of complaints about the built in thermostat malfunctioning and allowing the heater to overheat the tank. However, there are a lot of positive reviews about them too. I'd invest in a good internal thermometer and keep an eye on the actual tank temperature.
Plants and invertebrates only. The only fish I'd keep in a half gallon would very temporarily be a betta - as in during tank replacement or deep cleaning.