I have sand mixed with eco-complete. I had it in a 90 gallon about 3 inches deep for about a month. Then I tore it down and took it all out and the substrate smelled bad. Its been sitting in 5 gallon buckets for about a month now and still stinks. Not really bad, but it does have a noticeable odor when. Is it ok to put this stuff back into my tank when i rebuild it?