I ended up doing as you suggested last week. I got the tank up and running over the weekend, and used 5 gallons from my 55 gal at home. I am pretty sure the tap water was not the problem.
I also added some filter material from an established tank to jump start the bacteria population. I...
The heater is fine. The plants, decor and tank were all rinsed in water. I assume the nitrates are fine since I have done frequent water changes.
I had not considered phosphates.
Clarification: the 90% water change I did was tap water from home, not tank water from home. There were no fish...
I'm new to this forum, but not to fish-keeping. I have been keeping fish since 1974, when I was a highschool senior. The problem I am having is that 4 months ago I set up a 30 gal cube aquarium in the waiting room at work. I can't keep fish alive in it. I got through the new tank syndrome...