Sacrificial MollyMy 02 cents in there.... cycling the tank is essential.... I used to put in a sacrifical fish a molly or guppy to aid in that process. Water will turn cloudy then clear up... This is a microbial bloom and goes toward getting the filter started as well as adjusting the PH. Mollies are pretty tough and good for that job.
flakes in the gravel may be extra food... too much food will kill fish as well. Causing another bloom an anerobic bloom displaces oxygen not good.
Best to keep fish that have the same environmental requirements together.... Betas are brackish water fish so ar mollies platys guppies... The only consideration with betas is not to put in other betas even females. They nip fins of guppies or fish that have long fins.
Gold fish can handle a wide range of temperatures but do best in an un heated tank.
Remember For all fish the general rule of thumb is... an inch of fish per Gallon of tank. Has to do with Oxygen exchange.... If you add bubblers in you can increase that some but not a lot.
Ideal fish tank shape is as long as it is deep. surface area for oxygen exchange.
MY 110 gallon tank got a partial change of 25 percent about twice a year. I raised angel fish from quarter sized to the size of your palm and they were breeding. I did an undergravel filter along with a canister filter because the tank was deeper than normal. Along with a bubbler.
I also didnt feed but once every two days sometimes three.
Technology and husbandry has changed quite a bit since I started out but I had good instruction. Hung around an Ichthyologist at work Where we had two hundred aquariums fresh water on one side and salt on the other.
deb

