So you followed our previous post and set up a new saltwater aquarium, what now? Well, before you go adding living creatures you have to “cycle your tank”, which is lingo for letting enough bacteria build up in your tank and filter media to break down fish waste. Most filtration in a tank is biological, or taken care of by this bacteria, so having enough of it is a big deal.
Basically, when fish poo decomposes in your tank it releases ammonia into the water, the bacteria converts the ammonia into nitrites, and then finally the nitrites are converted into nitrates, which we remove with our regular water changes. This is called the nitrogen cycle. Look it up for a more detailed explanation.
Before getting started, you’re going to need a few things. Buy yourself a water test kit, I recommend this one by API for $25 on Amazon. This will give you the ability to see where your tank is at in the nitrogen cycle and check your pH. Before adding life to the tank you should also get a thermometer and a heater. Lastly, you’ll also need to buy some fuel to get the cycle started, I recommend either using fish food or a small raw shrimp, but more on that below.
Step 1 – Adding an ammonia source to the tank.
If you followed our setup guide and purchased live sand and live rock you will already have some of the bacteria we are looking for in the tank and now we need to feed it so it can grow and colonize on the surface of the rock and sand. There are multiple ways to do this and I’ll discuss them all briefly.
The best way in my opinion is to add a pinch of fish food or a piece of raw shrimp to the tank and let it break down on the sand bed. The decomposing food/shrimp will provide enough ammonia to feed the bacteria and get the nitrogen cycle going and this is the method I’m going with (fish food, not a shrimp, because I don’t to risk my room smelling like rotting shrimp).
The other ways I’ve heard of people using are adding pure, unscented ammonia everyday or, adding a live, hardy fish to the tank and allowing it to provide waste. The ammonia method will work, but to me it seems less natural and more tedious so I haven’t tried it, here is an article going over the idea if you’re interested. The last method, cycling with a fish, is one I do not endorse at all. Mainly because the fish has to live through the ammonia spike and the nitrite spike and if your tank is new they will reach toxic levels. At best, your new fish will get sick and stressed out, however, the more likely result will be the fish dying. Please have patience and use food/shrimp or ammonia when starting your cycle.
Step 2 – Monitoring water parameters.
After adding your ammonia source you need to begin testing for ammonia. You are looking for around 5 ppm on the ammonia test, it could take a few days for the levels to get that high if you’re using food/shrimp. Once the ammonia reaches this level, continue testing daily and watch for it to drop, this is the bacteria growing and converting the ammonia to nitrites. Continue to test for ammonia, but also start to test for nitrites as well. You want to see the nitrites climb and fall just like the ammonia did, I usually look for around 2 ppm as a nitrite spike. If yours aren’t getting that high, add more food or ammonia to the tank and continue testing both ammonia and nitrites. The goal is to build up large colonies of bacteria so it’s OK to let these levels climb, they are feeding the growth you’re after! The nitrite will take longer to drop down to zero than the ammonia but that’s normal, the bacteria that converts nitrite to nitrates takes longer to reproduce. Your goal is to see both ammonia and nitrite at 0 ppm and the nitrates anywhere from 20-40 ppm. Once this has happened once, it’s time to move to step 3.
Step 3 – Your first water change.
Now that nitrate levels are higher it’s time to export them out of our system. The best way to control the nitrate levels in a small tank that doesn’t have a sump system is to perform a major water change (50%-70%). In my 3 gallon tank I plan on changing out about 1.5 gallons and testing nitrate levels after.
To perform a water change, prep your new water by getting its’ salinity correct and heating it up to the temperature of your tank in a clean bucket(I’m using a back up heater I got from craigslist to heat and checking salinity with a hygrometer). Then remove the necessary amount of water from your tank ( I use a 3 foot piece of plastic tubing and siphon into a gallon jug.) and add the new water to the tank slowly so you don’t disturb the sand bed. Once you’re finished changing the water, test for pH and nitrates. If your nitrates are lower than 10 ppm, it’s safe to add a fish or a snail, but I like to add more ammonia fuel and go through the spike one more time. What I’m looking for is a rapid conversion from ammonia to nitrate, this is one spot in the cycle that I highly recommend using pure ammonia because you can quickly get the level to 5 ppm. The goal is 0 ppm on ammonia and nitrite in 12-16 hours after seeing 5 ppm on ammonia. If the tank can’t convert it that quickly, repeat steps 1-3 until it can so that you know you have enough bacteria present to support your livestock.
This might seem like a lot of tedious work, but remember that you are building a life supporting ecosystem in your home. Look out for an upcoming post on basic daily/weekly maintenance tasks in the next few days and keep checking in to see what’s new!