Cycling a tank full guide

 

HI FRIENDS!

 

Today I would like to talk about one of the most important parts of reef keeping. Cycling a tank! 

 

Before you attempt putting a tank together you should have a baseline understanding of how everything works and how you plan to care for your tank and livestock. Cycling a tank is often an after thought. It is really common for someone to go to a store, buy the tank and equipment, and then get overly excited and buy fish and livestock immediately. This is dangerous for the livestock in the tank because there will be a build up of harmful matter and chemicals such as ammonia, phosphates, and nitrate. It is also a big reason a lot of people get frustrated and leave the hobby. If a tank is not properly cycled then you will not be able to control anything for a long time. What I mean is you will more than likely have unwanted algae grow out of control and nothing you do will be able to help manage it. And because the tank was not cycled properly, you will be delaying the tank reaching peak maturity even if you do everything right afterwards.

 

Before you put fish or coral in a tank it is important to cycle the tank first. Essentially, you must take care of an empty tank for 4-8 weeks to build a healthy population of bacteria. This bacterium is the backbone and powerhouse of your tank. It works 24 hours a day and helps keep everything stable. The bacteria populate surfaces in the tank, typically in the form of sand and rock. The rocks are porous which means there is more surface area inside. This is the perfect home for deep nitrifying bacteria to grow.

This bacterium is very important for completing the nitrogen cycle for aquariums. It breaks down ammonia (NH3, which is very harmful to fish and other inverts) and then turns it into nitrite (NO2, which is still harmful but less than ammonia). The next step in the cycle is turning the nitrite into nitrate (NO3, this is the least harmful).

 

There are a lot of ways to start a tank cycle. The old method that a lot of people recommend is cycling with a cheap small fish. The fish will eat food and poop, causing nutrients to break down into ammonia. This is not as common anymore because of ethical reasons. The fish is harmed in the process and this method should be avoided. Especially that there are a lot of easy ways to get it done.

A tried-and-true way to cycle a tank (from scratch) is to blind feed the tank. Every other day (for a week) you will drop a few food pellets into the tank and let them decompose. This also starts the bacteria bloom without the need for a fish. The old school version of this was putting a single frozen shrimp in a mesh bag and taking it out after a week (yuck).

More recently, there has been a large push from the industry to cycle tanks with bottled nitrifying bacteria starter. At first, I was skeptical. But it really does work well for what it is. It can shave a few days off the cycle because it starts right away. The bacteria that are bottled will still need a food source (ammonia) to stay active. So, it is important to have some in the tank. Some people will pour a little bit of protein skimmer product into the new tank for this reason.

Finally, probably the most effective way to cycle a tank is to seed it with rocks or supplies from an already cycled and mature tank. This is normally done in addition with one of the methods listed above. Typically, someone will give or loan you a rock from their tank. The bacteria from that rock will spread to other places in the tank and help speed the process up. Other things that will work are dirty filter socks or filter floss, sponge filters, marine pure blocks, a cup of sand, and bio balls.

 

A word of caution. Even if you start a tank with cured live rock, live rock, live sand, or other objects from a matured and cycled tank, you will still have a die off of bacteria. This will cause a mini cycle while the bacteria population stabilizes to the new environment. Starting a tank with these objects is still going to be a safer and quicker method than if you started with dry material.

 

So now that you know a little bit about the nitrogen cycle you will need to know when it is properly done. For that you must test the parameters every few days. There are a lot of reliable test kits online. Some can be picked up fairly cheap now too. You only need to test for the three chemicals (nitrate, nitrite, ammonia), but for future care of your tank it may be beneficial to buy extra tests for calcium, alkalinity, PH, and a few odds and ends depending on your set up. After the cycle is complete you do not need to keep checking these three. The only exception is if you notice a problem with your tank. It helps trouble shoot what the cause may be.

When you start testing your ammonia will be high. As the cycle progresses it will drop and level off (still detectable). While that happens, the nitrite will begin to climb then drop and stabilize while the nitrate picks up. Finally, when the nitrate begins to drop the ammonia and nitrite will also drop further. Once you read zero for ammonia and nitrite your tank should be properly cycled and ready for fish and coral.

 

When you add fish or any livestock you want to do it slowly. Adding living creatures will be a lot of added bio-load which will stress the bacteria population. If you do too much all at once you may cause another cycle. This is also why it is important to plan your tank ahead of time. You should have a clear idea of what fish you will put in the tank in order to avoid husbandry issues. 

I want everyone to start this hobby happy and being able to enjoy their tank. A little delayed gratification will save you a lot of long term stress. If you have any questions about cycling a tank please let us know!

Thank you,

FFF