Nitrates dropped to 0

My best guess is this. Since you put in the filter media two months ago that was seeded with bacteria and the bacteria did not have a source of ammonia to work with they died. I'm not overly certain what the brown particles are. Since it is a planted tank you should keep testing your ammonia and nitrites. If they stay at zero you should be fine cycle wise. That is the plants may be consuming the ammonia before any bacteria has a chance to get at it. I would do water changes in any event just to try to vacuum out some of the brown particles. Personally speaking I'd stay away from the product Cycle. I haven't heard enough good things about it to say it does anything useful in a tank.

Your nitrates are probably 0 because it's a planted tank, this is one of the benefits of a planted tank. Plants consume nitrates as a source of food, if the bio load is light enough and the tank is not overstocked, then it's very possibly that there will be just enough nitrates to keep the plants fed. If this is the case then you may actually have to provide supplemental nitrogen. I believe a good level of nitrates is 5ppm (correct me if I'm wrong).

Another thing that could have happened is you could have added fish too quickly and caused the tank to re-cycle. Test your ammonia and nitrite immediately.

Also cycle is useless, read the ingredients. It's just water conditioner.

That's what I was guessing actually. I'd say keep measuring, but most likely your plants are using up the ammonia, nitrite, and nitrates in your tank quicker than they are being produced. I still don't know what your brown stuff floating about might be though.

To do List

1. You may need to clean your filter, swish it in used tank water during a normal water change. The brown stuff is probably filter "dirt" (actually bio-slime). You can clean the loose stuff off and there will be enough bacteria left to keep the filter going. You may find that a lot of the junk is plant material, my filters seem to process more plant wastes than fish wastes.

2. Nitrogen can be added by Seachem Fourish Nitrogen, or by finding KNO3 locally. Sources include local feed stores that carry KNO3 fertilizer (very cheap), pharmacies that carry "saltpeter", certain types of stump removers at the hardware store, plus several mail order sources. Also, fish food and fish are a great source of nitrogen, can you add more fish?

3. Brown stuff may be brown diatoms. That might go away by itself, or may require higher lighting. Also otocinculus catfish will eat that, as will Malaysian Trumpet Snails.