Blue Betta

Question
I have 2 new bettas - males - purchased 2 days ago, one red, one blue.  Bluefish doesn't seem to be doing well and I'm worried and want to do the right thing. I am all over the Internet getting conflicting information and don't know what I should be doing. I have a 5 gal tank with divider. Just gravel on bottom no plants yet, I'm worried about plastic ones hurting the fins.. I may get some moss, seems to be a lot of different people recommend it.  Anyway my questions...  
-Bluefish was bright in colour when we got him but after 2 days colour seems to be fading. He is very lethargic. When I feed him (once or twice per day???) - so far feeding once in morning he spits it out. I don't know if he finds and eats later?  Food is Aqueon Betta Food and is fine piecs but only havTe a small amt that came with tank, I have the same food in pellets.  He also looks as though he may have a small lump near his backside (?) should I give him a shelled Pea?
- I treat the water with conditiner, have a filter but no temperature regulator. Temp fluctuates between 78 and 84 ( when I have light on, should I keep it on??).
-Redfish is doing great, very active and responsive    
Your help is appreciated! I tried uploading a photo but the "choose photo" is grayed out and doesn't let mr, I can send in an email.

Answer
Deborah,
The main problem is the water temperature. The water has to be at least 80 degrees at all times. The best way to do this is with a heater, he is, after all, a tropical fish. If you leave the light on, you will then get algae, and no one wants that. He is new to his surroundings, and some fish take a little longer to get use to their new home. The cooked shelled pea is for when he looks bloated due to constipation. You can feed it to him any ways, it will not hurt at all. Make sure the food is a good quality pellet food. Flakes and powered food are not good for them. They also do not require the filter, and sometimes, the males do not like them. Just keep an eye on him for a few days, and once you add the heater, you will probably see a huge difference in him. Let me know if things do not get better in a few days, or if things get worse. You can send a pic to my email, jaymie_johnson1970@yahoo.com.