I have been keeping freshwater tropical fish for many years now. If you want to prevent problems with your aquarium and your tropical fish you need to carefully prepare your tank, even before you add fish.
Here is the sequence I used to prepare my aquarium for my tropical fish.
I selected a glass aquarium over acrylic because glass is stronger, easier to clean, does not scratch and will not sag or bend like acrylic.
I bought my tank from a store that specializes in all types of fish. So I was pretty confident in the selection I made that it would not leak. But just the same, you can save your self some grief by performing a leak test of any tank you buy.
Also at the time you leak test it; it is a good idea to clean your tank with warm water. Do not use soap or any other cleaning agent since it may cause problems with your fish.
Before putting in the substrate I placed an aerator at the rear of the aquarium. This way I can cover it with the substrate so it is out of view except for the bubbles.
Ensure you rinse the aerator with warm water to remove any contaminants before placing it in the aquarium.
If you are new to aquariums, you are probably wondering why they call that stuff at the bottom of your aquarium substrate. Substrate is defined as a substance that is acted upon in a biochemical reaction. When we develop an aquarium, we need to also develop bacteria to keep ammonia and nitrites out. This bacterium clings to the stuff at the bottom hence the term substrate.
The substrate I chose was gravel because for my weekly cleanings it is much easier to clean and I liked the look of it. I placed about 50 pounds of gravel in my tank as the substrate. I have it about two inches deep at the front of the aquarium, and gradually increased the depth to three inches as I approached the back of the aquarium and covered the aerator.
Before placing the substrate in, ensure you rinse it with warm water to remove the dirt. If you do not do this your aquarium will be cloudy and difficult to clean up.
I feel this was the most critical step. I obtained five five-gallon buckets, washed out the buckets and then filled them with hot water. I added a conditioner to remove the chemicals and let them sit overnight. I then added the water to the tank using a deflector to prevent disturbing the substrate.
Since I only added twenty-five gallons at a time, this process took me five days.
Filter and Heater
With the tank full, I then added the heater and set it at 77 degrees that is ideal for tropical freshwater fish. Ensure you keep the heater covered to prevent cracking the heater.
Next I placed the filter in and turned it on to start cleaning the water. Ensure you get enough filter for the size tank you select. For my 75-gallon tank I needed three filters.
Besides cleaning your water the filters will also keep colonies of bacteria that will remove ammonia and nitrites from your water.
I use live plants in my aquarium and when the water got to 77 degrees I placed wisteria in the tank. These are good for removing nitrates from the water and give your shy fish a place to hide.
Once I had my temperature up to 77 degrees, I placed bacteria in the tank. This step is important to prevent getting ammonia and nitrites in your aquarium. With all my chemistry parameters in spec, pH, ammonia, nitrites and nitrates, I placed three Blue Gourami in to start the nitrogen cycle.
With fish in the tank, waste and decaying excess food will start producing ammonia. Ammonia is toxic to your fish and will be kept at low levels by the bacteria you have placed in the tank. Initially you will see a slight ammonia spike but then it will drop off to zero.
The bacteria will consume the ammonia producing nitrites. Nitrites are also toxic to your fish but other bacteria that you have placed in the tank will consume the nitrites, producing nitrates.
Your live plants will remove nitrates and when you replace part of your water when you clean the tank.
Once your ammonia spike is gone and the nitrites are gone, you have established an environment that your fish will thrive in. The bacteria will keep your ammonia and nitrites at zero. The bacterium now resides on the substrate, filter mechanism and on the tank walls.
You can now start adding fish to your aquarium slowly. I added three a week so as not to upset the equilibrium I had established in the aquarium.