I built a 8 x 10 gallon rack over the Christmas break. I've been working on cycling the tank and wanted to report my experience. While planning this system, I found a product I'd not heard of before which claimed to allow cycling a tank within 24 hours. Not only that, but the particular bacteria it contained would actually convert nitrates into N2 as part of aerobic denitrification (usually this is done anaerobically by bacteria). But if this was so revolutionary why couldn't I find much written about it? I decided to give it a try anyway. I want to post my results so that others can (re)discover this product because it deserves to be better known.
HDLTD.com
With 8 x 10 gallons + 15 gallons in the sump there is roughly 95 gallons total. There is Hydroton as the bacteria media in the sump. I use this expanded clay material because I'm interested in keeping plants. According to Hiatt, if I used the recommended tri-base carbon, all the nitrogen would be scrubbed from the system which would not leave any for the plants. But the bacteria need a media that has extremely high surface area. Both tribase carbon and hydroton provide this amount of surface area.
At Hour 0 these were the water conditions:
pH 6.5
0 ppm Total Ammonia (Free Ammonia and Ammonium ion)
20 degrees Celsius
I dropped in 150ml of bottled Ammonia(NH3) which brought the system up to 5ppm Total Ammonia
At the same time I put in half a bottle of the Right Now bacteria (HDLTD.com)
36 hours later these were the water conditions:
pH 7.2
5 ppm Total Ammonia (NH3 and NH4+)
0.15 ppm Free Ammonia (NH3 only)
48 hours after adding the bacteria):
pH 7.2
> 6 ppm Total Ammonia (NH3 and NH4)
0 ppm Free Ammonia (NH3 only)
Just so the results are clear. Within 48 hours, all the toxic ammonia has been turned into non toxic ammonium ion form. I would have liked to test the nitrites and nitrates as well but unfortunately the used kit I have is faulty and I have to wait to get a new kit.
In any case, this is a totally surprising result (to me) and verifies the claims made by Hiatt on his website. He says in order to know that things are working correctly, test that the ammonia (toxic) has been converted to ammonium ion (non toxic).
As I said I would still like to verify nitrates, but the tank is cycled. And totally non-scientific evidence - the water smells like fish tank water does.