Thanks for all the replies. I did research Tropica soil and went for it as it was suppose too not cause a ammonia burst. But unless wood or plants can cause the ammonia, it is the only thing it can be. It's not a big problem, been told about something that can remove it, but as with everything I will watch the chemistry closely. It's a shame as two LFS are just getting new fish in after Christmas break, but will get there.