Sounds like a freak death.... minicycle may be kicking in... if you see diatoms and a lil more algae form than usual...is a small indicator. if the live rock ..the additional you bought was not cured...it may be curing in the tank releasing decay.
On a note about filtration. Canisters and HoB bio wheel types...work for fresh but are nitrate factories for salt water. Plan on purchasing down the road a skimmer...either hang off the back ..if sump(did you mention you had one?) a sump skimmer even better ...
Skimmer is the best filtration for a salt tank...read the sig below the link I have on them to expand on that more.
Start testing your water in the mid day and PH in the evenings for a few days to see if you are getting into a minicycle....
There is no way I can answer why anything died...all we can do from here is advise you on moving forward here in getting that 55 on the good path of stability.
Do some daily tests see how that goes... When you can get yourself a decent power head...I would say a Korilia #4 to start and get 1 or 2 more down the road. For now just get one in there for flow.
You can use your present filters just be sure to clean them out 2 to 3 times a week. Detritus will get trapped in the filters and break down...adding to your nitrate build ups.
For now keep your water changes around 15% a week till you can skim. Even then check your nitrates after a change out to make sure you impact the readings.
Keep us informed about how your tank does in a few days with daily tests logged ....its too hard for me to determine what the heck went goofy on you.
Let's just move forward from here on making that 55 a happy tank.
On a note about filtration. Canisters and HoB bio wheel types...work for fresh but are nitrate factories for salt water. Plan on purchasing down the road a skimmer...either hang off the back ..if sump(did you mention you had one?) a sump skimmer even better ...
Skimmer is the best filtration for a salt tank...read the sig below the link I have on them to expand on that more.
Start testing your water in the mid day and PH in the evenings for a few days to see if you are getting into a minicycle....
There is no way I can answer why anything died...all we can do from here is advise you on moving forward here in getting that 55 on the good path of stability.
Do some daily tests see how that goes... When you can get yourself a decent power head...I would say a Korilia #4 to start and get 1 or 2 more down the road. For now just get one in there for flow.
You can use your present filters just be sure to clean them out 2 to 3 times a week. Detritus will get trapped in the filters and break down...adding to your nitrate build ups.
For now keep your water changes around 15% a week till you can skim. Even then check your nitrates after a change out to make sure you impact the readings.
Keep us informed about how your tank does in a few days with daily tests logged ....its too hard for me to determine what the heck went goofy on you.
Let's just move forward from here on making that 55 a happy tank.
