I see no problem (notwithstanding it seems unnecessary) adding a bacterial supplement (like Dr. Tim's One and Only), but I would not not add ammonium chloride. This could kill plants, bacteria and fish. I assume this is intended to be an artificial ammonia source to start the cycle? Not needed with plants.
Plant cycling requires a good planting, including some fast-growing plants (floating are ideal for this). A few first fish are added, and the fish stock gradually increased. Plants need nitrogen, and most aquatic plants prefer ammonium (ammonia) so they take it up as it appears. A few fish plus their waste cannot possibly produce more ammonia than several plants will take up. Another benefit is that nitrite does not occur from this.
There is no ammonia above zero (using our test kits like the API) so fish are not harmed, and it gets the plants going fast. Now, some ammonia will get taken up by bacteria, this is bound to occur no matter what, and this in turn will mean nitrite, then nitrate. But the level of nitrite is not even measurable using the API or similar kit, and nitrate will be very low, no more than 5 ppm if that.
You do not want to be adding any artificial source of ammonia during this, as it may be more than the plants can handle and being toxic, could kill the plants, bacteria and fish.
I use this method for all my new or re-set tanks. Over the past couple of years I have torn down all my tanks, from a 33g up to 115g, to replace the gravel substrate with play sand. I replaced the filter pads and cleaned the media under the tap at the same time. Each tank was done in a day, with the exception of the 115g because of the amount of sand to wash and let settle. The fish were moved to a temporary running tank during the work on each tank, and moved back into the new set-up the same day or in the case of the larger tanks the next morning because I don't like moving fish near the end of the day but preferably in the early morning so they can be refreshed and have time to settle.
Byron.
