Ammonia from the supermarket can be between 5 and 10% ammonia. Using 9.5% to produce 100 ppm of ammonia in 200 l of water requires adding 210.53 ml. For 300l ppm that would be 315.79 l. When I cycled with store ammonia I was adding about 5 drops/10 gals of tank water. Today with the benefit of online ammonia calculators I would be adding. If I were cycling 200l to 3 ppm today I would be adding 6.32 ml of ammonia. Or are you saying you would be using 2 or 3 barrles for that volume of ammonia? I am confused by how you stated things. if i cycled two 50 gal tanks each to 3 ppm I am adding 6 ppm but not into one tank.
One of the few things science knows for sure about the ammonia oxidizing bacteria is that there are a number of different strains and that the particular strains that end up colonizing any given location (be it a tank, a pond a waste treatment plant etc.) depends upon the concentration of ammonia.
This is the reason why science tells us in the hobby that, when doing a fishless cycle, do not to let the ammonia or nitrite levels exceed 5 ppm as nitrogen. That translates to about 6.4 ppm for ammonia on the total ion kits common in the hobby. For nitrite this number is about 16.4 ppm on the total ion scale. If we exceed that linit we inhibit the stains we want and instead cuclture those that will not survive over the longer term. This is similar to saying that nitrification stops in acid pH. It does not. It becomes less efficient and may encourage some different strains, but it does happen. Similarly, salinity limits the diversity of the nitrifying bacteria in the water.
Next, the bacteria form colonies and it is the colony which handles the load. The size of the colony will increase or decrease with the availability of what they need. The situation we create in a tank in terms of cycling is not the same as what will be in the tank once it has become cycled. In the begining it doesn't matter whether it is done with or without fish. Three is no ammonia present and then there is. With fish the ammonia takes a bit of time to build up but it builds up due to the lack of bacteria. With a fishless cycle we add enough ammonia to result in about 3 ppm all at once. In either case, there is a point where there is and ammonia concntration present in the several ppm range. Once the bacteria have colonized and multipllied, that level of ammonia etc. should never again be detected unless something goes wrong.
So, let's assume a tank has been cycled and fully stocked. it doesn't matter how it was done. This tank is now creating ammonia 24/7, but at a fairly low level. In the absence of the bacteria that ammonia would accumulate. It might even add up to 3 ppm a day or more, but it will do so slowly and continuously. What this means is the bacteria we want in our tanks are not the ones able to handle and which require higher levels of ammonia and nitrite to thrive, they are the ones which can thrive in the lower levels created in tanks.
Think of it this way. We mostly eat three meals and maybe some snacks in a day. But we could not eat all that food tf we had to do so all in one sitting. The bacteria are not versatile in terms of being able to handle or thrive at any level of ammonia or nitrite, different strains are adapted to thrive at different levels. And then there is good old mother nature. She designed things to work the way they do. That is why different bacteria function in different environments. This is why when Dr. Hovsnec et. al. did the research into the nitrifying bacteria in aquariums, they found even when other strains were put into a tank being cycled, in the end specific strains always dominated and the other strains put in were often completely undetectable.
So, if one over doses ammonia in a fishless cycle the result will be the wrong strains will colonize. They will be fine on too much ammonia. But as the concentration of ammonia available goes down, those bacteria will be dying back. At the same time the bacteria which can thrive at the lower levels will be colonizing.The only question is will his cause and issues along the way.