bacterial infection

Sadly a few months ago 3 of my female bumble bee was hiding, not feeding and I suspect it was some bacterial infection that cause water retention issues and the frog couldn't disperse the water causing the bloated look and later die but now after 4mths or so I found the male which was pair with of one the dead female is showing the same symptom ,to prevent it from happening again.. I setup a totally new tanks for the males,clean and spray the tank with a water hose every other day and hoping that it will be fine but after 4 months,the nightmare is back!
I keep 2 frog in a 30cm(width) x 60cm(length) x30cm(height) to prevent over crowding and in the tank was ABG mix with sea grape leaves and some prothos plant.
I did some reading up that appropriate antibiotics could help and they mention treating the frog with fish antibiotics that contains any of the this three types of active antibacterial medications, Metronidazole, Ormetoprim-sulfa and Oxytetracycline ?

Had anyone use them before??

I be buying pedialyte tomorrow , do I use the full dosage or do I need to mix with water before spraying it on the frog?? Please advise.


Thanks