Flakes are a a poor source of ammonia. There are two good products to use for cycling. Both are ammonium chloride. Ammonia the gas (NH3) when dissolved in water turns mostly int ammonium (NH4) . how much of the total ammonia in one's tank is in each forms depend mostly on the pH but also to a lesser extent. temperature and salinity. Total Ammonia is the sum of NH3 and NH4. You can add or remove either and it will balance back out based on the pH and temp.
Here is what Dr. Tim aka Timothy Hovanec, PhD, who discovered the specific strains of nitrifying bacteria in aquariums.wrote on his site:
Using shrimp or fish food
One of the more popular fishless cycling methods is to buy a few dead shrimp at the grocery store, cut them up into chunks and add them to the aquarium. The shrimp decay, which produces ammonia to feed the nitrifying bacteria. There are a few drawbacks with this method, one being that the hobbyist really has no way to know how much ammonia is being produced by the decaying shrimp, and the aquarium does not look very good with dead shrimp laying on the bottom. Also, the organic material of the shrimp can cause bacteria blooms which turn the aquarium water cloudy. This method works but it takes time and patience and you will probably see a spike in ammonia and nitrite if you add a medium to heavy load of fish after the initial cycling. Note that some people use flake fish food instead of shrimp but this is not recommended because flake food does not have much organic material compared to shrimp and so does not add a lot of ammonia to the water, but you can use cut fish instead of shrimp.
Hint: to speed up the decay of the shrimp/fish and produce more ammonia, add some DrTim’s Aquatics Waste-Away sludge busting bacteria to the tank.
Using ammonium chloride
This is the other most popular way to cycle a fishless aquarium. Simply add chemical ammonia to the aquarium water and let the process cycle. The benefits of this method are that the tank does not cloud up with a bacteria bloom and you don’t have to look at an aquarium with dead cut up shrimp or fish on the bottom. Plus you can somewhat accurately determine the amount of ammonia being added to the tank. The drawbacks to this method are that the proper ammonia solution can be hard to find and when you do find an ammonia solution you may not be able to easily determine its concentration.
from
https://www.drtimsaquatics.com/resources/fishless-cycling/
So, as for the products you can use:
1. Dr. Tim's ammonium chloride.
2. Fritz Fishless Fuel
Both are liquids and get dosed in drops/gal to add ammonia. There is on caveat here , though. There are two different scales that can be used to measure nitrogen in water. This include nitrite (NO2) and nitrate (NO3). Science is usually concerned with only the nitrogen (N) in all three. So they measure using the Nitrogen Scale. However, most of the hobby test kits measure using the Total Ion scale which includes the Hs and Os involved.
The two above products use the Nitrogen scale. So if you are using the popular API tests, they use the Total Ion scale. The good part of all of this is it is easy for convert the two scales into each other like we do for miles and kilometers etc. Also, depending on whose instructions you use for fishless cycling, you should know which scale it uses for measuring the ppms involved.
Both the products above direct one to add 4 drops/gallon of water to produce 2 ppm of ammonia. This is using the Nitrogen scale, if your kit is not an API but another brand, it should tell you what scale. if not Google it. The above product's 2 ppm will be 2.56 ppm on the Total Ion scale.
I wrote several cycling articles for another site like this one in 2013. They are still there today. The primary one was on doing a fishless cycle adding ammonia and did not deal with the use of live plants which changes things up a bunch as they use ammonium while the bacteria prefer to use ammonia but many can use ammonium but less efficiently.
My cycling instructions call for adding 3 ppm of ammonia using the Total Ion scale. Here are the conversion factors converting between the two scales. Measurmenets using the Nitrogen scale will normally be followed by -N or -n. Unless you are doing a higher pH tank, using the 2ppm amount of the 2 products should work for freah water. It is also a lot easier to calculate dosing if it is a single step of 4 drops X the number of gallons of water in your tank.
Nirogen Scale-N ------ >Total Ion Scale
Ammonia-N (NH3) x 1.216 = Ammonia
Ammonium-N (NH4) x 1.288 = Ammonium
For Total Ammonia I use 1.280 as most of the ammonia in water
Nitite-N (NO2) x 3.284 = Nitrite
Nitrate-N (NO3) x 4.426 - Nitrate
Btw- I set up my first tank 25 years ago next week without cycling it properly. I returned most of the fish and promised to buy them back down the road and then I did a proper fish in cycle. That is the only time I did that. I started doing fishless cycling with ammonia for my tanks and filters after that. For some time I used plain household ammonia with no scents of other additives except for a very small amount of surfactants. I always ran carbon when using this ammonia and did a huge water change after the tank was cycled and before I added close to a full fish load all at once.
And then I learned about ammonium chloride and switched to using that almost 20 year ago.
