Betta Fish: New to the Betta world

What kind of live plant?
The tank is 3.5 gallon. He was a gift, I scrambled and got a tank quick. I plan to get the 5 gallon in the next few months.

Yes plastic will damage their tails

Hi OP, the tank is too small and without a heater the fish will suffer with a lowered immune system and be prone to sickness.

Please get a heater and a larger tank. 5 gallon is the absolute minimum size, though 10 gallon would be significantly easier to maintain and keep stable. Live plants recommended, these plastic ones rip the fins and bodies of fish plus add nothing to the tank.

Do you have a water parameter testing kit for ammonia, nitrite, nitrate and pH? Normally before we add a fish to a tank we spend 4-6 weeks or so growing the good bacteria of the nitrogen cycle. These good bacteria are needed as new tanks turn toxic to fish very fast and can seriously harm, even kill them.

Without testing the water, you’ve no way of knowing if it’s safe for the fish at all. Liquid test kits such as the API Master or NT Labs freshwater are accurate and last ages. The accuracy and testing of all crucial parameters (ammonia, nitrite, nitrate and pH) will be especially essential to a beginner.

Fish waste releases ammonia which is highly toxic and burns the fish alive – the fins, skin, eyes and gills. Very nasty. Good bacteria exist that process this toxic ammonia into nitrite. Nitrite is still highly toxic and stops the blood carrying oxygen causing suffocation and haemorrhaging. More nasty stuff. Thankfully more good bacteria exist that convert nitrite into nitrate which we keep at safe levels of below 20ppm with regular water changes. In a tiny tank with no live plants water changes will need to be 2 X a week minimum. However we’re not at this stage yet as it’s not nitrogen cycled and we haven’t got the good bacteria in your tank yet.

As the good bacteria has not been established before adding the fish, you’ll need to do what is called a fish in nitrogen cycle. This requires accurate testing often daily, and daily water changes to reduce the toxin build up in the water.

As it’s been 2 days the toxins will be getting high by now so please do a water change – always use a dechlorinator. Please also invest in the liquid water testing kit, a heater and a bigger tank.

Here is more information on nitrogen cycling, growing the good bacteria and how to keep your fish alive during the toxic phases of a new tank. There are decent pictures of healthy looking tanks that fish feel safe and healthy in the articles too:

1.
https://www.aquariumcoop.com/blogs/aquarium/nitrogen-cycle?srsltid=AfmBOoo0c5qm6BMn8cI3Yg3a5-qryssL2APY3eAeBuNg9254IjsTg4yP

2.
https://aquacadabra.com/blogs/news/how-to-cycle-a-fish-tank-the-beginner-s-guide

3.
https://www.practicalfishkeeping.co.uk/features/how-to-cycle-a-fish-tank-the-complete-guide/