First Actual Betta

[Perseusmom]

If your tank is a 3 gallon I would got ahead and get a 25 watt heater the Elite brand are very good heaters. Yes leave him in the tank when you do water changes less stress. Good luck he is a very handsome guy !

[Kanra Chan]

My boyfriend has a crown tail just like that!
You are right, there is probably no fin rot, it is coloration.
That being said, you need to pay special attention to the edges of those fins because fin rot and injuries will not be as obvious on him as it would be on other bettas. There was a suggestion to put pantyhose on the filter, however pet stores sell soft, porous covers for the filters that you just slip on the exterior. It refines the filtration system and creates a lower flow. It also eliminates the possibility of your fish being sucked in.

[Nicci Lu]

I would get a 25 watt heater for your 3 gallon. The problem with the smaller heaters, like 7.5 watts, is that their temperature is pre-set and you can't manually adjust it. This can lead to temperature fluctuations, especially at night when most people turn their home heat down. You want a heater with manual temperature adjustment.

Eheim Jager and Hydor Theo are both brands that are commonly recommended. Aqueon Pro, too (not the regular Aqueon, has to be Pro), but I'm not sure if they make a 25 watt. I love my Jager- it keeps my tank a steady 78 and I never have to play with the temperature settings.

Marina and BiOrb silk plants are good brands. Try to buy one in person- many silk plants have plastic pieces that will need to cut. My silk plants from Petsmart had to be sanded down on the silk leaf edge because they did not pass the pantyhose test. There is a thread on here about how the Petsmart ones also contain metal that can become exposed. If you want to go with live plants, java fern is nearly impossible to kill and is a good beginner plant.

[Kanra Chan]

Also, aquarium salt is very necessary.
If your fish is already in bad condition, as well as having been moved into a new environment, his immune system might be a little impacted. For instance, if you use salt in your water, your fish will never get ich.
However, I agree that it is not necessary right NOW. Some bettas have a bad reaction to salt when they are already stressed / adapting, so the small amount you used is good.
Also, salt helps kill bacteria around open wounds and infection (Like fin rot, if that is what he has), and promotes new slim coating which protects scales and fins, and makes the fish look more vibrant.
In the future, you may want to consider using salt (In varying levels - the same amount of salt each time will lose it's effectiveness as the fish and the bacteria in the water will develop an immunity, same as medicine. I personally put salt in every other batch of water for the water changes, so the levels remain inconsistent) as part of your tank maintenance.

As far as the plants go, I use silk ones, and while I have no experience with real plant, from what I gather you would have to have sand or fine gravel for the plants. If you are okay with that, I'd say go for it, as plants seem to have their own waste-reducing benefits and provide good hiding places. If you are getting a silk plant, get one that mimics the colour of your fish if you can. He may feel safer, or you may see some interesting chameleon effects. :)

If he doesn't eat, that's normal since he just got a new habitat. So you have a waste remover (Looks like a turkey baster)? Those things are excellent for water changes where you don't want to remove the fish. I bought mine for $2CND.

My boyfriend's 2.5g tank has a heater with a thermometer that self-regulates and keeps the water at a certain temperature. If you are getting a heater, a self-regulating one is best. If you think your tank is too small, I assure you, you can find one specifically for your tank size.