Fishless Cycle

Set up your aquarium and equipment.
Add a conditioner to neutralize the chlorine and chloramines in your tap water.
Install a strong air pump for vigorous aeration for the oxygen loving nitrifying bacteria to flourish.
Turn the temperature up to 84-86 degrees to speed up the cycling process.
For saltwater tanks use a high quality alkalinity buffer and bring your alkalinity up to 175-200 mg/L (11-12DKH)
Add 1-2 drops of PH down per 5 gallons to add a source of phosphates for the nitrite-digesting bacteria.
Add a tiny pinch of flake food to add organic cofactors to feed the bacteria along with the ammonia.
Add an ammonia source
I don’t suggest adding shrimp or fish food to provide an ammonia source as the rotting food will also create other undesirable bacteria.
Instead, I suggest you use ammonium chloride or PURE liquid ammonia.
If you decide to use liquid ammonia make sure it is free from any added scents, surfactants or detergents as these are toxic to fish.
Add enough liquid ammonia or ammonium chloride to bring your ammonia level to 2-3ppm.
Some people suggest using gravel or seeded bio media from an established tank but beware of that method as along with the nitrifying bacteria you could be introducing unwelcome parasites or other disease.
A much safer method of seeding the tank with nitrifying bacteria is to use Culture Plus, Culture Max or both to introduce millions of nitrifying bacteria guaranteed to be free of any pathogens.
Test your ammonia and nitrites every other day and add enough ammonia to maintain an ammonia level between 2 – 3 ppm.
If you accidentally overdose and your ammonia level is higher than 4ppm do a partial water change to bring it down to 2-3ppm. Too high of an ammonia level can kill the nitrifying bacteria which will slow down your cycling time.
Once your ammonia starts to drop you will see a rise in your nitrite level.
This phase of the cycle is typically slower as the nitrite-digesting bacteria are slower growing than their ammonia-digesting counterparts.
If your nitrite levels rise higher than 4ppm do a partial water change as too high of a nitrite level will also slow down your cycling time.
During heavy biological activity your PH and alkalinity will tend to drift down quite quickly and too low of a PH will slow down or stall your cycle.
Do a partial water change to raise your PH.
For a freshwater tank make sure to keep your PH around 7.5 which is a happy medium for the different types of nitrifying bacteria.
For saltwater keep the alkalinity between 175-200 mg/L (11-12DKH) and your PH around 8.
Once you enter the nitrite phase of the cycle test your water daily.
At this point you will start to see nitrate levels rising.
When your aquarium can process the ammonia and nitrite completely in 24 hours, meaning you have 0 ammonia and 0 nitrite, your aquarium is fully cycled and you are ready to add fish!
At this time I suggest doing a 50% water change and lowering the temperature back down to 76 – 78 degrees.
Make sure you add the fish within 24 hours to insure there is an ammonia source to keep the bacteria alive.