Lethargic, droopy fins-but hanging on

[klingcam]

My betta doesn't seem to have any physical affliction (i.e. ick, bacteria, etc) except for perhaps his fins being a little thin and not spread in all his glory. However, he's been lethargic for a couple of weeks now and hides at the bottom of the tank in his rocks. It was recommended that I change the water at least once a week (he's in a 1/2 gal. tank), we use Amquel Plus water conditioner per the mfg. instructions, and were told to feed every 3 days to avoid bloating and cut the meal size from 5 pellets (Hikari Betta Bio-Gold pellets) down to 3 pellets. He gets no other type of food. We were also advised to use Revive, so I got some. The instructions on the Revive state:
"Use 1 drop per 16 ozs of water daily for at least 3 days....discontinue use after a cure has been achieved...Treatment should be discontinued after 7 days".
So we put in 4 drops for his 64oz (1/2 gal) tank when we changed the water, and left him in it for 3 days, changed the water, and used the revive again for another 3 days. He looked no better, but no worse either. I changed the water again, no medicine this time, and he went a week. But still no change. Droopy fins and lethargic. I am trying the Revive again now. One question I have is with the wording on the Revive instructions. Do they mean that we should add the 4 drops of Revive to the existing water each day? or change the water each day but continuing to medicate each water change with 4 drops? I would think that continually adding the medicine to the same water would over-medicate him immensely. What are your thoughts? Also, I read online that Indian Almond Leaf is very good for Bettas. I'm willing to get it and try it if it's a valuable treatment. Also, a Betta enthusiast in a forum suggested that for we change his water daily for at least a week and add some Aquarium salt, so we've been doing that for a week. Water is same temp as his water.He seems no better...but no worse.Any suggestions are greatly appreciated.

Housing
What size is your tank? 1/2 gal.
What temperature is your tank? 78 deg.
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? No
What tank mates does your betta fish live with? None

Food
What type of food do you feed your betta fish? Hikari Betta
Bio-Gold pellets only
How often do you feed your betta fish? 1x (3 pellets) every 3 days. We were feeding every day, then every other day, but were told every 3 days is better.

Maintenance
How often do you perform a water change? 1-2 x per week
What percentage of the water do you change when you perform a water change? 100%
What type of additives do you add to the water when you perform a water change? Just 5 drops Amquel Detoxifier (and
now 1/2 tsp. aquarium salt)

Water Parameters:
Have you tested your water? If so, what are the following parameters? No

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? Droopy fins, and very lethargic.
How has your betta fish's behavior changed? Hides alot. Swims up and then lets himself fall.. but he does eat all when fed.
When did you start noticing the symptoms? 3 weeks ago.
Have you started treating your fish? If so, how? Have done Revive 2x.
Does your fish have any history of being ill? Not prior to this.
How old is your fish (approximately)?4-5 months

[ZackyBear]

In a tank that small, water changes should be done daily, or every other day to prevent ammonia build up :c

I'm thinking it's ammonia poisoning...

[klingcam]

Been about 10 days changing water each day...and I made an error in my original post: he has been getting 1/4 tsp. aquarium salt with each change, not 1/2 tsp. Still no change. Top fin looks haggard and he still hangs on the bottom and hides alot. Also, seems like his gills are working overtime. Anyone?

[Mahachai]

I am not sure, but since he's laboring his gills it could be gills disease? If he's not eating, maybe you can try live/frozen foods. You should post some pictures and maybe that'll give members an idea.