The gravel does need cleaning, and you can get small gravel vacuums for that.
A cheap way to do it is to just get a flexible length of clear hose/pipe about 4 feet long , stick one end in the tank and swirl it about just above the gravel to stir up any crap.
Suck sharply on the other end of the hose to pull the water in and start the flow, and
very quickly point that same end into a bucket to catch the dirty water.
Keep the end that's in in the tank swirling all around over the gravel, and this will suck up any bits of crap and empty them into the bucket.
Be careful not to suck your fish up the tube.
Make sure you're not overfeeding your fish. If you are and he's not eating all of it, you will make more work for yourself and pollute his water even quicker, because the uneaten bits will sink and rot on the bottom.
I feed mine every other day in small amounts, once in the morning and once in the evening.
To be fair, the main bulk of bad information with regards to bettas on websites, is in three areas. Tank size, heating and filtration.
Many will reccomend that you keep a betta in a couple of gallons because they still believe that bettas live in puddles for most of the time and that they don't like big spaces. Utter bullshit of course.
Many will also say that as long as you keep the room warm the tank doesn't need a heater. Again, utter bullshit. Unless you actually live in Thailand where the heat is pretty constant most of the year, your betta absolutely needs a heater. It's a tropical fish and needs a steady temperature.
And of course, many say they don't need a filter because they can breathe air. Those two things have nothing to do with eachother. They need filtration to maintain a steady biological environment in the tankwater. The bacteria inside the filter process the fishwaste and do that for you.
The breathing air thing is a survival mechanism for when their water sources in the wild dry up and heat up, making the oxygen levels in the water too low for normal breathing.
The care of a betta is exactly the same as any other basic tropical fish . They are anabantoids, and are closely related to Gouramis.
Simply look up basic tropical fishtank care. It's just a matter of weekly water changes, check all equipment is working, check all fish are alive and healthy, feed everyone what they need feeding when they need it.
They all need the correct size tank to keep a stable environment and have plenty of space to swim, they need the correct temperature provided by a heater, and they need filtration and weekly water changes to keep the biology of the tankwater stable.
Doing all these correctly will give you a healthy fish and tank.
Here is a website listing tropical fish diseases with pictures.
http://badmanstropicalfish.com/fish_...cation.html#TB
Whitespot, otherwise known as Ich, is a very common one, and very easy to identify. Given good tank care, your fish shouldn't display any signs of disease, though it is very possible he could have developed or caught something in the store.
Don't medicate him unless he is showing definite signs of illness or disease. If he's swimming and eating, and not lethargic and hanging in a corner or the surface all the time, he should be fine.
Some bettas are more active than others, they all have different personalities. Some are very territorial and flare at their reflections all day, others are really lazy and chilled.
