One of the biggest factors that goes into starting up a new aquarium is being able to test the water. As mentioned previously in the Nitrogen Cycle article, there are a lot of factors that go into play when establishing a cycle for aquariums. You need to look at the spikes and fluctuations in ammonia, nitrites, nitrates and pH levels. These are all necessary to the longevity of your aquarium and the life that dwells inside it. If your ammonia, nitrites and nitrates do not fall to ZERO before the cycle is complete, there is a risk that any living organism you introduce into the tank may die. Too much ammonia can lead to anoxia or poisoning. Nitrites in itself are poisonous, so any level of this can be fatal to fish. These are just a few reasons that you want to make sure you are testing your water correctly on startup, as well as periodically throughout the course of your aquarium’s lifespan.


What To Do

There are many kits out there which can test all of these parameters, and even more that can test calcium, magnesium, calcium carbonate, etc. levels for reef tanks. The first thing you will want to do is research which brand of test kits are recommended and do not give false positive or false negative readings. Please note that many saltwater aquariums can take up to 4 weeks before a cycle is complete, and there is no reason that you should rush this process… as tempting as it can be. Rushing any of this will cause detrimental problems down the road which you will not want to try and fix.

So after you purchase your test kit, you are going to want to test the water weekly, before and after the addition of any marine life. This is essential not only to see how well your tank is progressing, but also to make sure all of your parameters (aside from pH, which should stay relatively constant at a 7.6-8.6) are dropping at a gradual pace over time. Once your nitrogen cycle has finished via your test readings, you should now be able to introduce coral and fish.


But Wait, There’s More!

Sometimes a test kit can give a false reading as mentioned above. This is especially true with the cheaper brands such as the generic testing strips and even API chemical tests. The color range of these can be sporadic and these two types of kits are known to give a broad ballpark range on parameters, which may not be 100% accurate all the time. This is why if you’re unsure about a specific reading, then try another type of test kit out or go to a local aquarium shop for them to to a test on a water sample. There is no reason to risk adding any livestock in before you are absolutely sure the water is safe. Saltwater fish, and especially corals are expensive, and many stores will not return deceased marine life. On this note, it is also important to test your water any time a fish dies in the aquarium. This will help with the oversight of any spike in ammonia or nitrate that may occur.

Example of a test strip


I would also like to elaborate on testing your water weekly after the introduction of fish and corals. This is normally a must, and many aquarium enthusiasts will agree. Small changes or additions into the aquarium can affect the parameters of your water. For example, adding in certain types of fish may in turn increase the nitrate level of your water. Or adding in coral could deplete your minerals such as calcium and magnesium. This is especially true with nano and pico tanks. These tank sizes are renowned for fluctuations in water quality, so it is vital to constantly monitor these types of tanks.

Larger tanks with no recent introduction to new marine life can get away with less frequent testing. However, if you feel that the tank is slightly overstocked then I would recommend staying at a 1 to 2 week test to ensure the quality is stable. Algae is also a contributing factor to the quality of aquarium water. Algae can deplete oxygen in the water and can bloom in a single night’s notice. It’s important to tackle these things as they come up rather than waiting weeks to do any type of maintenance. You will save yourself a headache and the potential loss of fish if you do. Remember, aquariums are living ecosystems as well as a hobby so make sure you treat it as such!