After reading through this thread I'd like to offer two observations: one is that you have a nice looking tank there. The second is that I think you really need to take livebearerlove's advice and check your water parameters.
If I am reading correctly, you asked after 15 days if anyone thought your tank could be cycled after you got zero-zero-zero readings, and someone said it definitely could be. But according to what I've read, you didn't use any media from an established tank, you didn't add any store-bought bacteria, and no store-bought ammonia. There's nothing wrong with not using any of that, but if what I've read is correct, I seriously doubt you established a cycle in 15 days.
I think you should check your water parameters. At this point, 40 days into it and after adding livestock, you could *now* have an established cycle. But, I think you lost your livestock because it was not cycled.
If I'm wrong, I'm wrong. If not, then at this point you need to feed the bacteria by adding more livestock or by adding something like Dr. Tim's Ammonium Chloride until you do add livestock.
Again, nice looking tank, it'd be terrible to give up on it now.
Thank you, I thought it was a great looking tank as well. But having it at work was too much trouble. They would lower the AC here over night so I was having to add water every morning. Not too much of an issue but they did the same thing over the entire weekend. So the pump would keep the display area nice and full but the filter area was losing it's water. I was finding that on Monday it was close to running dry so my filter media was drying out every weekend.
I asked if it could have been cycled as I am new at planted tanks. Knowing that the plants would consume the junk in the water, I was not sure if it was safe to add animals before a cycle was done.
Anyhow, Tuesday of last week was the last day that there were any plants or anything in the tank. On Wednesday I hopped on an air plane and went to Mexico for five days. Knowing that I was not going to be around for five days and finding hair algae on everything after the weekend I pulled all the plants from the nano.
I took them home, did a bleach dip and put them into my 150 tall at home.
This week I am going to empty the tank and take it home. I will set it up again but somewhere I can keep an eye on it every day. SWMBO may not be happy as that will make three tanks at home. But I would rather have it at home and healthy than here at work and always being a problem.