The alternative would be to actualy cycle the tank by adding a a layer of gravel and some kind of aeration (like a small airstone or filter). It'll cycle just like an ordinary tank but will need more frequent water changes than a large cycled tank due to the small size (not every day though). You shouldn't change all the water at any time though - about 80-90% is sufficient if the tank's cycled. If the tank's cycled, there should be no algae/diatom problems any more after a few months and it'll also be a more stable environment for your betta.
As far as extra food goes - don't feed any more even if the betta still looks hungry. Just a couple of pellets (though it depends on what pellets you use), is enough. It's far better to 'underfeed' than to overfeed. Keep in mind that a fish' stomach realy isn't very large at all and even a single pellet is quite filling (though you may want to feed more than once a day if you only give them one
).
As far as extra food goes - don't feed any more even if the betta still looks hungry. Just a couple of pellets (though it depends on what pellets you use), is enough. It's far better to 'underfeed' than to overfeed. Keep in mind that a fish' stomach realy isn't very large at all and even a single pellet is quite filling (though you may want to feed more than once a day if you only give them one
).
