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Setting Up Your First Fish Tank

Nano Planted Low Tech Shrimp Aquarium

Nano Planted Low Tech Shrimp Aquarium

Fish Tanks

Curious about setting up your first fish tank or nervous to take the plunge into the fishkeeping hobby? Overwhelmed by all the options like fish tank sizes, heaters, filters, and lights it's easy to get discouraged and avoid the hobby. But in actuality fishkeeping is simple and fun. This article will go over the following topics.

  • The Nitrogen Cycle
  • Fish Tanks/Heaters (whats a good first size)
  • Filtration
  • Water Changes
  • Substrate
  • Fish Stocking

The Nitrogen Cycle

Before the fishkeeper starts their first tank they need to understand how we are able to keep fish in our aquariums and that is the nitrogen cycle. The Nitrogen Cycle is simple 3 step process. Which is Ammonia converting to Nitrite then to Nitrate. The last being the least harmful to fish in low quantities.

All living beings create ammonia by just living they eat and drink and then create waste, ie. poop and pee. In the aquarium this occurs in our fish too, but when they poop and pee they contaminate the water they swim in. How our fish tank takes care of this toxic waste and keeps our fish safe is the Nitrogen Cycle or aka our biological filter. Bacteria grows everywhere in the tank but its mostly concentrated in the substrate and the filter. Check the video below to learn more about it. But to keep it simple ammonia is created by fish waste, this is toxic to our fish. Bacteria builds up and then eats the ammonia and converts it to nitrite. Nitrite is really toxic to fish and needs to be zero or it can lead to fish death quickly. Lastly the nitrite is converted to nitrate. Nitrate is safe for fish in low quantities. When a tank is properly cycled a tank should never have an issue with nitrites unless something throws the tank out of balance, ie adding to many fish at once, cleaning the filter to much, removing the substrate. Any large change where this bacteria collects can lead to nitrite spikes.

With this a tank normally takes about 2 - 4 weeks to cycle. You can speed this up by adding fish food, or bacteria from the pet store. Another quick way to cycle a tank is grabbing substrate from a mature tank, and using the water also. There are a bunch of ways to mature the nitrogen cycle quickly but make sure it is complete. Easily testable, when you set your tank up you should see zero nitrites. As time goes on nitrites will have increased. When you see the nitrites start decreasing and get to zero the tank is matured and ready to go.

Nitrogen Cycle

Fish Tank/Heater/Lights

Next up is Fish Tank size, Heater and lights. These are together because they work in tandem. You will need a heater that can heat the size of fish tank you purchase, and a large enough light to go across the tank. That being said I will go into what size tank worked best for me and others when first starting out.

When you begin the hobby you normally will see aquariums from 1 gallon up to 125 gallons in pet stores. Where do you start though? I want to make this simple so first things first. Larger tanks are easier to manage then smaller tanks, why? This is because it takes more to throw them out of balance. Imagine a 1 gallon tank and a capful of bleach next to it and then it accidentally falls in. The tank will probably experience a large shock instantly. But now picture a 75 gallon in the same situation as before. The capful of bleach falls into the 75 gallon. This is still going to be damaging to the tank but it won't be as catastrophic as the smaller tank.

With that I would recommend beginners staying away from anything under 10 gallons and above 35 gallons. I say stay under 55 gallons because a 55 gallon tank becomes a commitment during water changes. A 35 gallon tank is the perfect size to begin with in my opinion its large enough to hold a decent amount of fish and pretty easy to maintain. Find a heater that's slightly larger than the tank and you are good to go. With lighting some tanks come with a lighted hood and others. If you get LED make sure its adjustable so it's not to bright that it causes algae. Do set up your light to only stay on 8 hours a day. Anything more and it will cause algae.


Filtration the life block of the fish tank do not skimp here, if you can't afford a larger filter downsize your aquarium size to meet your fish tanks needs. There are different type of filters to choose Hang on Back (HOB) Filters, Internal Filters, and Canister Filters. I personally stay away from internal filters because they are an eye sore in the tank and you can get much better performance out of HOB's and canister filters.

Filtration Size

Keep your filtration to about 3 to 5 times the size of the aquarium. For example a 10 gallon aquarium would be best fitted with a 30 gallon to 50 gallon filter. When a tank is over filtered it helps keep the water clean and buffers from fish overstocking issues. The only downside with oversizing is sometimes if your tank doesn't have much decor the flow from a larger filter can cause the tank water to move to quickly. This is easily fixed by turning down the filter if it's adjustable, or placing more decor in the tank to break up the flow.

Canister Filters

These are my favorite. They require the least amount of maintenance in between cleanings. You can leave a canister filter going for 3-4 months before it should be taken apart and cleaned. Another feature is they are whisper quiet normally, depending on brands. They also have adapters to relocate the heater outside the tank which creates a better looking tank. Canister filters are one of the best options for a fish tank in my personal experience working with most filter types.

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Hang on Back (HOB)

These are cheaper than canisters, require more frequent maintenance, and are louder. They still work great and you can add multiple to a fish tank to get adequate filtration. These require cleanings/replacement filtration parts 6-12 times per year. They have a minor cost that adds up over time, which makes me avoid them. The only plus to these are they are quick and easy to clean compared to the canister. Drop a new filter pad in and you are good for another 1 to 2 months.

Water Changes

Filtration is not the only thing that cleans the fish tank. A water change is a must every 1-2 weeks, this removes the excess nitrate from the nitrogen cycle. The aquarium doesn't need a full water change though, rather a roughly 20-30% water change is adequate. Replace the water with dechlorinated water and it's done.

This needs to be done or you will experience algae outbreaks and or Old Tank Syndrome (OTS). OTS is when new fish when added will die because all other inhabitants have been accustomed to high nitrate water.

To change water you get a siphon and a large container to hold the water from the tank and remove the 20-30% of water. Then dump the container and refill with same temperature water and pour into the tank carefully. With larger tanks this takes time and can be a heavy task if you want to be quick. Smaller tanks such as nano are easy with a normal siphon but when you get to anything above 10 invest in the Python. Save your back, save your time, save the hassle. A normal siphon is approximately $10-$20 dollars. A 25ft Python is $40. All you do is hook it up to the sink and it will siphon the water for you, change the switch and it will fill the tank. I left a link below because I believe in this product for fish keeping.

Python Easy Clean


There are many choices for substrate but they are broken down into two categories inert and aqua soils. The best choice for the fishkeepers first tank is inert substrates such as gravel. Gravels are easier to clean, and they last forever. Another plus is that when people start cleaning the gravel with a syphon the gravel isn't removed. You are also able to grow the easier plants such as Valiseneria and Anubias with a gravel substrate.

As experience is gained and if you pursue a planted tank aqua soil becomes a must. They absorb ammonia, nitrate, and provide nourishment for the roots of plants unlike gravel. But these breakdown over the course of a few years and must be replaced when they lose there shape.

Fish Stocking

Normally the 1" per gallon rule is utilized by fish stores everywhere and is conservative. The 1" per gallon rule is simply 1" of fish per gallon, so you buy a fish that gets to 4"s you have used 4 gallons of aquarium space. Also take into account the thickness of fish a skinny 4 inch fish is not the same as a 4" thick fish. The 1" per gallon rule is highly debated online and has been disproved by many fishkeepers everywhere. This is because everyone's tanks are different and have different ways of dealing with fish waste. For example these tanks are normally heavily planted, filtered and experience large water changes on a weekly basis. This means its possible it just requires more work to be successful. Stay away from more difficult set ups until you have the experience to manage more difficult bioloads. Stick with the 1" per gallon rule in the beginning and you will be safe and have a good first experience. Then slowly begin experimenting safely with larger bioloads to see what works for you.


In summary, fishkeeping is simple and also not as demanding as getting a dog as a pet. But keep these few things in mind and you will have a successful tank.

  • Nitrogen Cycle, make sure you cycle your tank before adding fish
  • Fish Tank size bigger is better and easier to maintain for the beginner
  • Filter is rated 3-5x bigger than your fish tank
  • Water changes 20-30% every 1-2 weeks
  • Substrate stick to inert substrates like a gravel for your first tank
  • Fish Stocking 1" per gallon. Conservatively stock your tank in the beginning
  • Light's on less than 8 hours a day

If you follow these simple rules your fish tank will be successful and easy. Hopefully it brings you joy and you start getting into aquascaping or even salt water tanks as your experience grows. Glass cubes with life are peaceful and beautiful to watch in your home. If you have any questions or comments please leave them below and I will answer. Let me know what you would like me to write about next for fish tanks, how to grow aquatic plants, nano tanks ect.


This content reflects the personal opinions of the author. It is accurate and true to the best of the author’s knowledge and should not be substituted for impartial fact or advice in legal, political, or personal matters.

© 2020 SquatchPrince

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