Betta and tank

Question
I have two male bettas. The last few weeks they have been getting sick. Red had "popeye" twice and Blue has mouth fungus. I've had them for 6 months I think and they've never gotten sick. I am wondering if it had anything to do with with new artificial plants I got them for their tanks (2.5 gallons) because it was shortly after that they began to look funny. But, also the heaters broke (I got new ones)so I don't know if the water temp. was at fault. I was wondering if it had anything to do with the plants because Blue's plant had a big layer of this filmy white stuff at the bottom of it. What is that? These are my first fish. I'm trying!  I also wanted to know if I need to get one of those things that make bubbles. Is that important? And how long does it take a betta to get better after you give it the medicine? Would my bettas be happy with a tank mate? Do they care? And, last question, is it uncomfortable for the betta if the filter is on too high? Thanks.  

Answer
Hi Sabrina;

The most important clue you gave me was "the white stuff" at the bottom. It is from rotting food. I think what happened was when the heaters broke the temperature got too low for them to digest properly so they may not have eaten much either. The excess food has now caused toxins to rise so the fish are getting sick easily. Clean the tanks out to get rid of the rotting food and they should start to feel better. They may still need medication but cleaning is a good start.  

Here is info on popeye;

http://www.fishjunkies.com/Diseases/popeye.php

Here is info on mouth "fungus" which is actually caused by flexibacter bacteria;

http://www.siamsbestbettas.com/diseases.html#Flexibacter

Bettas are just fine all alone. Even when they breed they chase the female away once the spawning is over. Just little loners by nature. The tank is pretty small for a tankmate anyway.

Bettas prefer slow water movement. You could add a bubbler but they really don't need it. Bettas breathe by taking gulps of air from the top to store in their "labyrinth". That's why you see them doing that every so often. This special organ allows them to live in very still and very low oxygen water. They don't need a lot of agitation in their water but a filter is a good thing. What they do need is clean water. Even with a filter the water needs a weekly change. Replace 25% to 50% weekly. Clean the gravel at the same time to avoid water quality problems. Food and waste get stuck in there and as you now know, it can make them very sick. I use a little tiny aquarium siphon with a larger tube at the tank end for cleaning the gravel in my 2.5 gallon betta tank. You do not have to remove the fish to clean every week. To get the crud out at first after this "white stuff" collecting you will have to drain and rinse everything though. After that, just a partial water change every week is fine.

I hope they feel better soon......

At Your Service;
Chris Robbins