Fishbone,
First off WAAAAY too much ammonia! I assume you mean 5 mg/liter and not 5%(
!!!). If you have 2000 gallons (which I assume are US gallons and hope you used the meter when filling up) that comes to about 7,500 liters. A 1 liter bottle of ammonium hydroxide is about 5% or 50 grams of ammonia gas. I find a reading of 0.25 mg/ltr gives me the best cycling result. This would be about a 40 milliliters for a little more than 2 grams of ammonia
My guess is you now have this pegged off the the scale I'm willing to bet if you dilute the pond water to 50% you will still show 5 mg/liter. My figures show that 1/3 gallon is about 70 grams. You should be closer to the10 mg/liter than 5. This is much too much and will retard the growth of nitrite consuming bacteria which will not establish until this figure comes down to about 2-3 mg/liter
What ever you do don't add any more.
Did you dechorinate the water as well?
B.Scott