I agree that you may have an ammonia spike in the tank.
This is a 5 gallon so I'd do a 4 1/2 gallon water change. Be sure the new water is the same temperature as the water in the tank and don't forget the dechlorinator.
It won't hurt the frogs to have that big of a change as long as you don't shock them with with water that's either too cold or too warm, and as long as you have removed chlorine and chloramine.
Could you get a ruler or tape measure and measure from the bottom to the top of the tank so we can know how tall it is exactly. Your water level is a little low in the photo but you said it was about 15 inches to the surface, so I just wanted to make sure.
Also, could you show us a photo that allows us to see the substrate. I'd like to get a look at how much gravel you have in the bottom of the tank. Food and debris can get down in the gravel and accumulate, so you have to vacuum regularly to remove that or you will have serious problems with water quality.
There are siphon vacuum systems that are pretty cheap at Walmart or Target or pet stores that allow you to suction the gravel and suck up decaying food, gunk, poo and debris. You don't need to spend much money on one for a tank that size.
Speaking of tanks. Four frogs in a 5 gallon is a bit small, so in the near future it would be good if you could upgrade to a 10 gallon. This would give them more room to swim and play, and would improve the water quality which is most important thing.
You mentioned putting your hands in the tank frequently; there's nothing wrong with that as long as you don't have any lotion, cream, sun screen, cologne, or soap residue on your hands, wrists and arms. Frogs are very sensitive to chemicals and even a tiny bit of residue on your skin can get in their water and cause problems.
I always washed my hands, wrists and forearms good, and then rinsed thoroughly, rubbing and scruffing my skin under running water to rub of any residue. Then dry with a clean paper towel, so I didn't get a fabric softener residue off of the towel onto my hands.
Be carefuly spraying air fresheners or room deoderizers, or any aerosol, really, in the room near them. In fact I always covered the tank with a towel if I was using windex or furniture polish spray or anything that might be airborne and drift over into their tanks. Amhpibians really are sensitive to chemical exposure. I'm not trying to freak you out:nilly: with scary warnings, things will be OK... you just have to exercise some care.:dance2:
Your little girl under the filter is probably OK. These little guys have the strangest behavior that is, to them, perfectly normal.
They can float... spread out in this spaced out zoned out way... it is called their "Zen" mode. I've seen mine drift slowly down... land on one foot with body in this stange ballet or ice skater pose, one leg out arms up.... pause for a moment and then just slowly fall over on their back like they just died. Then scramble up and zoom off to hide.
I've seen mine squeezed between the heater and glass side of the tank, looking like it was in a catatonic state... then have it swim happily away.
You do need to watch out for anything in the tank that they may squeeze into but then can't go further. It's hard for them to back up. It is possible for one to squeeze himself into a space that has no wiggle room and he can't go forward and can't back up... one could possibly drown in a situation like that.
The girl floating under the filter intake; if she doesn't move away after a while I would worry, but she's probably just found a neat place to hover.
If she is puffy looking, like she's swelling up, let us know. Try to get her to move so we can see her better if you think that's happening to her.
It's hard to see her, but from what I see she looks alright.
This is a 5 gallon so I'd do a 4 1/2 gallon water change. Be sure the new water is the same temperature as the water in the tank and don't forget the dechlorinator.
It won't hurt the frogs to have that big of a change as long as you don't shock them with with water that's either too cold or too warm, and as long as you have removed chlorine and chloramine.
Could you get a ruler or tape measure and measure from the bottom to the top of the tank so we can know how tall it is exactly. Your water level is a little low in the photo but you said it was about 15 inches to the surface, so I just wanted to make sure.
Also, could you show us a photo that allows us to see the substrate. I'd like to get a look at how much gravel you have in the bottom of the tank. Food and debris can get down in the gravel and accumulate, so you have to vacuum regularly to remove that or you will have serious problems with water quality.
There are siphon vacuum systems that are pretty cheap at Walmart or Target or pet stores that allow you to suction the gravel and suck up decaying food, gunk, poo and debris. You don't need to spend much money on one for a tank that size.
Speaking of tanks. Four frogs in a 5 gallon is a bit small, so in the near future it would be good if you could upgrade to a 10 gallon. This would give them more room to swim and play, and would improve the water quality which is most important thing.
You mentioned putting your hands in the tank frequently; there's nothing wrong with that as long as you don't have any lotion, cream, sun screen, cologne, or soap residue on your hands, wrists and arms. Frogs are very sensitive to chemicals and even a tiny bit of residue on your skin can get in their water and cause problems.
I always washed my hands, wrists and forearms good, and then rinsed thoroughly, rubbing and scruffing my skin under running water to rub of any residue. Then dry with a clean paper towel, so I didn't get a fabric softener residue off of the towel onto my hands.
Be carefuly spraying air fresheners or room deoderizers, or any aerosol, really, in the room near them. In fact I always covered the tank with a towel if I was using windex or furniture polish spray or anything that might be airborne and drift over into their tanks. Amhpibians really are sensitive to chemical exposure. I'm not trying to freak you out:nilly: with scary warnings, things will be OK... you just have to exercise some care.:dance2:
Your little girl under the filter is probably OK. These little guys have the strangest behavior that is, to them, perfectly normal.
They can float... spread out in this spaced out zoned out way... it is called their "Zen" mode. I've seen mine drift slowly down... land on one foot with body in this stange ballet or ice skater pose, one leg out arms up.... pause for a moment and then just slowly fall over on their back like they just died. Then scramble up and zoom off to hide.
I've seen mine squeezed between the heater and glass side of the tank, looking like it was in a catatonic state... then have it swim happily away.
You do need to watch out for anything in the tank that they may squeeze into but then can't go further. It's hard for them to back up. It is possible for one to squeeze himself into a space that has no wiggle room and he can't go forward and can't back up... one could possibly drown in a situation like that.
The girl floating under the filter intake; if she doesn't move away after a while I would worry, but she's probably just found a neat place to hover.
If she is puffy looking, like she's swelling up, let us know. Try to get her to move so we can see her better if you think that's happening to her.
It's hard to see her, but from what I see she looks alright.
Your story was HILARIOUS! And also for the advice. I have one on my camera, I'll have to upload it tomorrow. 
And they love their coral, two are hiding in it now 