We came home from a 3 day vacation to a tank crash. All the life stock, fishes, hermit crabs…, in my 50 Gal. 3year old, FOWLR tank were dead ! Only a bumble bee snail was some how still alive ! We have named it Morgie, after the star of the Nat Hist Museum’s Hall of Mammals movie about the lone survivor of event that wiped out the Dinosaurs. The circuit breaker to the tank tripped I am therefore pretty sure my tank crash was caused by mechanical failure, electrical that is. Lately I have had problems getting my Powersweep power head to restart after water changes. I am pretty sure it was an electrical failure in my Powersweep power head and caused it to become live in the tank and electrocuted all my live stock. The fishes were not just dead; their insides were all over the tank too. It was ugly. Should have replaced the Powersweep head at the first sign of trouble, learned my lesson the hard way. My question is -> now what ? 
I’ve replaced all the water from the tank with fresh water because the old water was very cloudy and smelled real bad, stank the entire house. I also rinsed the live rock and put them back. I did not remove the substrate. After one day of running a filter and skimmer the water is now clear again. However, Nitrate is about 5 to 10 ppm but the ammonia is through the roof !. I am guessing the my tank is going through the whole “tank cycle” again. Before the crash my numbers were all zero, only Nitrate was about 20 to 50 ppm. Unlike my Reef tank, I always had problem keeping Nitrates very low. Only the other hand, I have only lost a Coral Beauty in this tank before this.
I am wondering if I should replace the live rock or substrate, or both. Does such a tank crash necessitate such drastic measures, which pretty much means starting all over ? I don’t see any of the worms that you see in the substrate, against the glass, moving. But then again, I don’t remember seeing them move much anyway. Is there a way to tell if they are dead ? If they are all dead, would I need to change all my substrate ? The substrate I use is more course than I would like, about 1/16 inch. Since it appears that my thank is cycling, would now be a good time to add an additional inch of finer agroniate for the snails and hermit crabs to have an easier time moving around ?
On the preventative side of things, I believe there is a device that tracks electric leaks of devices in tanks. Would this have help prevent what happened to my tank ?
I’ve replaced all the water from the tank with fresh water because the old water was very cloudy and smelled real bad, stank the entire house. I also rinsed the live rock and put them back. I did not remove the substrate. After one day of running a filter and skimmer the water is now clear again. However, Nitrate is about 5 to 10 ppm but the ammonia is through the roof !. I am guessing the my tank is going through the whole “tank cycle” again. Before the crash my numbers were all zero, only Nitrate was about 20 to 50 ppm. Unlike my Reef tank, I always had problem keeping Nitrates very low. Only the other hand, I have only lost a Coral Beauty in this tank before this.
I am wondering if I should replace the live rock or substrate, or both. Does such a tank crash necessitate such drastic measures, which pretty much means starting all over ? I don’t see any of the worms that you see in the substrate, against the glass, moving. But then again, I don’t remember seeing them move much anyway. Is there a way to tell if they are dead ? If they are all dead, would I need to change all my substrate ? The substrate I use is more course than I would like, about 1/16 inch. Since it appears that my thank is cycling, would now be a good time to add an additional inch of finer agroniate for the snails and hermit crabs to have an easier time moving around ?
On the preventative side of things, I believe there is a device that tracks electric leaks of devices in tanks. Would this have help prevent what happened to my tank ?
