[Fishes electrocuted]

There is a ground probe called "ULTRALIFE ULTRA GROUND (TITANIUM GROUNDING PROBE)" that you can buy. However you might need some DIY skills to hook it up to a 3 pin plug head. My tank used to have stray electric and each time i do maintenance i would get a shock. After i got the probe and DIY it, plug it into a power socket WITHOUT turning the power on, no stray electric any more. 

[Frogspawn issues]

My frog spawn also produces slime when fed. Apparently from what i know, its their feeding response.