When dealing with a pond (or aquarium) of several hundred gallons,
is there ALWAYS a dangerously high ammonia spike following by a high nitrate period, even if the pond or aquarium is stocked fairly low (say, for instance, 4 inches of fish per 200 gallons, or a one inch fish per 50 gallons. ). Is it just a case of it taking longer to build up to the harmful levels? I guess what I'm asking is, do the levels of each phase of the cycle have to hit a "peak" before the next phase can begin, or can the bacteria work with even small amounts and have a tank successfully cycle with no dangerous ammonia / nitrite spikes (or barely detectable level). Also, does the period of time that only plants are in the system count toward the nitrogen cycle, or do the nitrifying bacteria need a steady supply of fish waste to survive, thus when putting a fish in a month old plants only tank, the cycling process would be pretty much the same as with a freshly filled tank. The reason I'm asking is because I want to avoid the necessity of having to do large volume water changes, i.e., 40 gallons of water a week, out of 200. I do realize that every time I add more fish I would start a new mini-cycle, just want to avoid the dangerously high spikes.

"When dealing with a pond (or aquarium) of several hundred gallons,
is there ALWAYS a dangerously high ammonia spike following by a high nitrate period, even if the pond or aquarium is stocked fairly low (say, for instance, 4 inches of fish per 200 gallons, or a one inch fish per 50 gallons. ). Is it just a case of it taking longer to build up to the harmful levels?"

There is not always a spike. When I set up my 1800 gallon pond and stocked it lightly in 1997, I monitored the levels of ammonia and nitrite weekly for a few months and never saw any levels beyond the margin of error as being negative results (close to nothing basically). I've also set up aquariums and not seen any ammonia even when starting one from scratch. I do weekly 50% water changes on my tanks and add good bacteria weekly so that helps. The nitrogen cycle is a biological process so it's never over. It's not like after 2 months, ding, time is up, the ammonia and nitrite are all now zero. If the bacteria can grow fast enough to keep up with the animals' waste load, there may never be any real readable ammonia or nitrite.

"I guess what I'm asking is, do the levels of each phase of the cycle have to hit a "peak" before the next phase can begin, or can the bacteria work with even small amounts and have a tank successfully cycle with no dangerous ammonia / nitrite spikes (or barely detectable level)."

That is what I too have read, that the levels have to grow enough so that the bacteria for the next stage can multiply enough to handle them. That may be the case in a tank or pond with a lot of fish in a controlled situation but reality doesn't always match laboratory tests. I did see that peaking of ammonia and nitrite once when monitoring a new setup but that was a 3 gallon tank with 8 tiny fish! So, that was a case where the bacteria didn't have the time to grow fast enough to keep up. If there's just say one colony of good bacteria, they can utilize that first small amount of ammonia. As the ammonia available goes up, the colonies multiply. The problem comes if there are no good bacteria to start so seeding with an established pond or aquarium helps a lot as I think it helps to add good bacteria (like Stress-Zyme, Cycle, BZT, etc.) although some people say they don't work. All you really need is to get that colony going and not overload them with "food" (fish waste, ammonia).

"Also, does the period of time that only plants are in the system count toward the nitrogen cycle, or do the nitrifying bacteria need a steady supply of fish waste to survive, thus when putting a fish in a month old plants only tank, the cycling process would be pretty much the same as with a freshly filled tank. The reason I'm asking is because I want to avoid the necessity of having to do large volume water changes, i.e., 40 gallons of water a week, out of 200. I do realize that every time I add more fish I would start a new mini-cycle, just want to avoid the dangerously high spikes."

Plants also consume nitrogen, and yes, I mean ammonia directly sometimes in addition to the end product of nitrate. So, they are part of the nitrogen cycle as well. The plants don't really produce much to feed the good bacteria although rotting plants probably provide a little. A plant probably that you add to the pond is not "just" a plant but also contains microorganisms, tiny animals, snails, algae, good bacteria, etc. attached to it; things to not only seed the good bacteria but perhaps feed them some as well. The nitrogen cycle won't really kick off though without the animal waste. I think the cycle would be faster and safer in an established plant tank or pond then a new sterile tank.

If you add the fish slowly (and smaller fish too help) to your 200 gallon pond over time, you may never have to worry about ammonia or nitrite spiking, especially if it's well planted. Even is you put in say a dozen tiny goldfish, things would probably be ok at first since they don't produce much ammonia when tiny in 200 gallons. Of course, once they grow and grow and spawn, 200 gallons would be overstocked with a dozen foot long goldfish. Which species of fish were you interested in and how many did you plant to add?

I definitely would not put in a dozen goldfish, I know how big they get eventually!
Right now I am trying to get some feeder rosy reds healthy enough and I'm treating them with Aquarisol in a small tub (as I posted in another thread). There is one feeder goldfish, too, he is very small, about the same length as one of the biggest rosy reds. I realize that is rather crowded for the 25 gallon tub, but of course it is easier to do water changes and medications, etc. in a tub than in the pond, that's why I'm curious to what happens when they "graduate" to the pond, and if I can expect to do the same amount of water changes. I do not have a nitrite test kit so I am erring on the side of caution. No ammonia detected so far.
I have had them in the tub for one week, and right now (8) eight of them are left from the original dozen.

Also question about their feeding habits....the rosy reds all seem to be bottom feeders, even the goldfish. They are fairly active, but stay at the very bottom of the tub for the most part. I also have fatheads in a separate tub and they do the same, picking at stuff off the bottom. I tried various kinds of foods, and interestingly, they seem to be attracted to sinking algae wafers. The tub is about 12 inches deep, the pond is 2 feet deep. Will they also tend to swim at the very bottom of a 2 foot deep pond, and feed from the bottom? If so then I will really have to be careful about not overfeeding since I probably will not be able to see if they are eating what I put in.

Sorry, I didn't realize you were the same person from another thread about the rosy reds. I go through so many e-mails that I don't usually bother to try to match names, etc. I certainly recommend rosy reds for the smaller ponds. Your one goldfish who escaped from certain death as a feeder will be a good addition to your pond because a single goldfish will never produce offspring.

You're going from a tub to a pond almost 10 times bigger so managing the water chemistry will be much easier, and water changes don't have to be as extreme. Aside from the end of March 50% water change with cleaning and topping it off as needed, I never change water in my 153 gallon rosy red pond.

Your fish are probably feeding from the bottom because they feel most secure down there. Once they settle into a pond with vegetation and other places to hide, they will become more adventurous as they become less scared. Remember, so far their life has been a series of attempted and successful nettings which are very scary for them. My rosy reds spend a lot of their day near the bottom of my 153 gallon, 2 feet deep pond too but always zip to the top to feed off the flakes I put in. The clearer the water is (it just went crystal after a month of suspended algae), the more time they spend on the bottom in order to hide and feel secure. Until your fish settle in, feed lightly.