Cycle Moving Faster Than Usual

[LyraGuppi]

I'm cycling a 90 gallon at the moment, and expected it to move slowly, but it's doing the opposite. Here's my cycle notes so far:
 
Day 1: Dosed 3 ppm of Ammonia
Day 2: -
Day 3: -
Day 4: Ammonia at 2ppm, Nitrite at roundabout 1 ppm
Day 5: -
Day 6: -
Day 7: Ammonia at .50 ppm, Nitrite at .25 ppm, Nitrate at 5 ppm
 
I know the Nitrate tests can be inaccurate, so I can't go solely off of that reading. I shook the bottles, tested twice, checked expiration dates just in case (they are all in date), but nothing changed. Did the bacteria just process everything very quickly? The tank is heavily planted. No old filter media or sand were introduced, the only way bacteria could have been brought in is through the plants I bought.
What should my next step be? Test again? Start over? 
 
(On a side note, I have root tabs ready for the plants. Should I push those in now, or after the cycle?)

 

[LyraGuppi]

I suppose for now I'll add another 3ppm and see how it goes.

 

[StevenF]

 
 
Did the bacteria just process everything very quickly? The tank is heavily planted. 

Plants like bacteria need nitrogen to live.  If there is enough phosphate and potassium along with trace nutrients in your water the plants will absorb Ammonia, nitrite, and nitrate.  If you can immediately get plants to grow they will control ammonia and nitrite and maintain a healthy tank.  However if you never have grown plants before it is bast to cycle the tank with Ammonia and then add the plants to a cycled. tank.  
 
http/www.fishforums.net/index.php?/topic/299827-why-we-should-not-fishless-cycle-planted-tanks/
 
Doing a cycle with plants in the tank is not ideal because too much ammonia and nitrite can kill them. I would continue with the cycling and I would go ahead and add the root tabs.   they might help the plants withstand the ammonia. and might speed up the growth of bacteria and the plants..

 

[LyraGuppi]

Ok, will do.