Help with bacterial diseases

[Fiish]

Hi all, I have problems of bacterial diseases in my tank, it all started with pop eye in my coral beauty angel, then frayed fins and medicate with rxp kent marine, but I don't complete the drug treatment, was finished and could no longer get it again, now the coral beauty angel began with ich and again fins frayed and pop eye, I'm trying to Cupramine but only ich disappeared, today we see more sick and tired and have not eaten.I think not much time left, and I want to know how to eradicate these diseases from my tank, what should I do to remove them? or I start from the beginning? remove everything and start cycling with new rock and new water? I have live sand from Nature's Ocean and i don't want to waste, my live rock have a long time underwater, and i don't want to waste too, so what i do now? :uhoh3:

 

[billsreef]

Bacterial diseases are typically secondary to other issues. First step, tell us about your tank. What size, filtration, list all fish, water quality parameters for pH, ammonia, nitrite, nitrate, and salinity.

 

[Fiish]

My tank is small, not have a large dimensions and I was planning to have 3 or 4 small fish only. Approximately I have 50 kg of live rock.
Main tank 65 gallons and sump of 25 gallons. I not have skimmer, have several years with water changes, but in recent months my previous tank broke and I had to take all my fish,I had many years without my fish sick.
I use my living rock from the previous tank, and take to change my previous substrate and started to cycle again in a new tank since May, and added 2 fish in August but after a few days the problems started. All my levels were in order, and I think it was all a mistake when I was acclimatizing, accidentally I added water transport of one of the fish in my tank. I have this levels:
Ph=8.3
Ammonie=0
Nitrite=0
Nitrate= 5 mg/L