Is your tank cycled ? (are you familiar with the cycling process ?) - I am not familiar with this process (in name at least), but I do not change the water more than every 3-6 months. We judge based on how poorly the gravel is beginning to look. We do regularly (at least weekly to biweekly) net out debris/uneaten food. I use Stablility by SeaChem once a month as directed on the bottle. I just freshly changed the water in our newish tank (3.7gal). We downgraded from a 5gal. because it was just too much to manage and the filtration system didn't seem great. The tank now is cube shaped (Petco brand), the old one was the Fluval Spec and was rectangular. It has a carbon filter as well as a biological one, along with the sponge and a pump.
Are you testing your water with a liquid test kit (like the API test kit) or dipsticks ? Yes, ran tests since this happened.
Ammonia: 0.25ppm (seemed to be between 0 and 0.25 based on the color, but since this result I attained new filters, sponge and emptied all but an inch of water, replaced it with Great Value bottled water, and added the capful of Stability by SeaChem)
Nitrite: 0
Nitrate: 0
pH: 7.4 (checked prior to water change)
KH: unknown
Temperature: unknown (but the house temperature is probably somewhere in the 60s, and the water I added was at room temp)
Are you using a heater ? No
Are you using any aeration / bubbler ? No
Water change amount/frequency: 3.7gal tank. Just today changed all but 1 inch of the water
Tank size/how long in operation: 3.7gal./about 1 month
Filtration: Carbon and Biological, along with a enzyme sponge and pump.
Water additives/conditioners/pH adjusters: Stability by SeaChem
What, how much and how often are the fish/frogs fed: Reptotreat whole bloodworms (1/2 a tube/pouch) once a week. It seemed like a lot of food for them.
Tank inhabitants (number, size and type of fish/frogs): 2 African Dwarf Frogs - the sickly one is significantly skinnier now, but always was. The other frog appears to be in good health.
New additions/changes to the tank: Tank is one month old and a downgrade in size from the 5 gal. Fluval Spec to the 3.7 cube-shaped petco brand. Added a two-tiered rock cave (big one on bottom and small one on top) with 2-3 holes in each - this doesn't offer significant areas of concealment, since the holes are fairly large. Am considering buying another ornament that would be better for them to hide in if this is an issue. This only takes up one side of the tank, and the other side is bare. Also added white gravel (larger stones than in past, is the "glow" brand)
Unusual findings on the fish/frog: None (which is what is puzzling to me - not even a color change)
Unusual behavior: Extremely lethargic, to the point where he hardly moves and only does so occasionally and when nudged by the net at times (I don't nudge hard and realize that they can be fragile). I do want to note that I do keep checking and he is still alive, as I will see occasional movement of his arms or back leg. He cannot turn over when turned upside down, nor seemingly swim more than about a half inch at a time - which he does very infrequently. He was fine during the day 3 days ago, and this started (at least from when I saw) that night, and I had checked him at noon prior. No red marks, no discoloration, no discharge, no loose/shedding skin, no obvious injuries, no bloating, no obvious signs of infection, and he has not floated to the top and cannot swim much at all (cannot swim up). He just sits where he is at the bottom of the tank for the most part. When I did find him on Friday night (the first night of symptoms, 3 days ago), he was upside down and as stated, couldn't flip himself right side up and I aided him with the net and brought him up for air. He will open and close his mouth occaisionally as well. He was smaller than our other frog to start, but appears much thinner than usual. I did feed him on Friday (the first night of symptoms) evening, and he did shove his head into the food I placed right next to him and appeared to eat his way through it. So he is eating it seems. I do bring him up with the net for some air about 2-4 times a day (I think I am correct that they need to come up for air every so often). I should also note that when we did do the tank change, one of the frogs (unsure which) jumped out of the cup I had him in as I was transferring him into the new tank onto the bureau and then to the floor. After gently scooping him up, he did this again. I am fully aware that this may have caused him injury, and feel terrible about it. Again, no injury is apparent. The bureau is just under 5 feet tall. The other frog is acting and moving normally, with no signs or symptoms, eating well, much larger than the other and appears normal overall. We did note that since the tank change they have stopped trying to mate with one another. The frogs were originally from Brookstone and we were told that they were both male. The frogs are about to turn 5 years old in March or April of this year, but we do not know how old they were when purchased (assumed they were fairly young, if not essentially new frogs). They have never had health issues in the past to our knowledge.
Medications/what has been tried or done do far: Water change, feeding, API Master Test Kit (All Tests Performed as shown above), Filter Change, Sponge Change, Stability from SeaChem added.