Thanks!
I am currently having a problem with the fish - they keep dying.

I have tested the water and everything is supposedly fine. Good Ph, good nitrate, nitrite, ammonia and alkalinity. I tested it with kits at home and at took it to the pet store for testing...
So now I need to figure out what is going. The tank was circulating water for a several days prior to putting fish it. I then put in 4 tetras so they could start the the tank cycling. I did my water changes and conditioned the water. But they still died.
Now I plan on pulling everything out - cleaning all the surfaces inside, washing the gravel, and possibly adding another layer of epoxy over the foam.
So here are my current suspects for water contamination:
1. Foam (or more specifically the paint on it..) The epoxy covering is designated safe once cured, but there may be insufficient coverage over the painted foam. It is possible that some sort of contaminant is leaching into the water and the tests cannot detect it.
2. The silicone. I am using what is labeled as 100% pure silicone. It makes no mention of any anti mildew or anti microbial qualities. I had read elsewhere that silicone of this type should be fine - but perhaps that was bad info. So I will remove all of it(or as much as I can) and use silicone purchased directely form the pet store that explicitly says aquarium safe.
3. Fertilizer. To the best of my knowledge, there should be no fertilizer getting into the water - the planted areas are sealed away from the wet area. But I cannot dismiss the possibility of contamination. So when I drain the tank, I will look for leaks from the planted areas.
4. residual industrial contaminates in the plumbing system. This seems like it should be pretty low risk... All tubing and piping is human potable grade. Normal PVC piping and vinyl tubing. But you never know.... SO I will do several full system flushes.
5. the water. There could simply be something nasty in the water. I have been using tap water and adding in an aquarium water conditioner that depletes the chlorine and is supposed to make it safe. I guess I will try distilled water.
Anyone have any suggestions?