Aquarium Water Testing - When and What Should You Test

New Aquariums 

As someone new to freshwater aquarium keeping you are probably wondering what   Aquarium Test Kits you should have and how often you should be doing them.  

What you are trying to do through aquarium water tests is maintain the water quality at a level which is best for your fish so the first thing to do is understand the sort of conditions that your chosen fish prefer. All fish will live happiest between certain water parameters and this varies with each type of fish. 

In a new tank there is no nitrogen cycle.  The biological filter is not yet established so any fish waste or undigested food will lead to an Ammonia Spike.  This is the first stage of the Nitrogen Cycle and can be easily detected with an Ammonia Test.

You need to test aquarium water regularly as the nitrogen cycle gets established.

As the friendly bacteria start to grow you will see the Ammonia Spike replaced by a nitrite spike as the Ammonia is converted to nitrite by the first set of friendly bacteria. This is stage two of the Nitrogen Cycle and can be tested for with a nitrite test

Finally as the second set of friendly bacteria take hold you will see the Nitrite spike replaced by a Nitrate spike.  This is the third and final stage of the Nitrogen Cycle which will show up through a Nitrate Test.

Depending on whether you are using starter fish to cycle your tank or going the fishless cycle route, these spikes will tend to be more or less extreme. If you are using starter fish, you will need to carry out aquarium water testing frequently and carry out partial water changes to maintain water quality for your fish.

Both Ammonia and Nitrite are harmful to fish.  It is only when nitrite levels have fallen back to their original levels that it is safe to either start adding fish (fishless cycle) or add more fish (starter fish cycle)

Either way make sure that you add the fish slowly, a few at a time, allowing the nitrogen cycle to catch up each time.  Test the water every couple of days while you are adding fish and carry out a partial water change (up to 30%) if there is an Ammonia or Nitrite spike.

This cycling process can take several weeks and you cannot tell which stage you are at without testing the water.

So the three test kits that you definitely need for aquarium water testing simply to monitor the nitrogen cycle are Ammonia, Nitrite and Nitrate.  The fourth that you need is pH to test the acidity of the tank.

Whenever you are introducing fish you need to make sure that there isn’t too big a difference between the pH level in your tank and the pH level of the tank that they came from.  If there is you need to acclimatise the fish carefully to avoid shock and stress.

Established Aquariums

Once your tank has matured, you still need to test but fortunately not as often. Testing your water regularly and making a note of the results can alert you to any changes before they have the chance to turn into problems.

Make it part of your routine to test the water before you carry out your regular water changes, and definitely if your fish are acting differently.

One of the biggest problems in a mature tank is nitrate. Yes, it's far less dangerous than ammonia and nitrite, but the trouble with nitrate is that it often begins to rise over time. Your planting and regular water changes will go a long way towards dealing with nitrate but it is still worth monitoring on a monthly basis.

One potential problem with high nitrate levels is when you introduce new fish. Unlike your old fish who have gradually become accustomed to your water quality, new fish experience a shock when introduced to a tank with high nitrate levels and can fall ill and die within a week if this is not monitored.

Nitrate is also food for algae which will thrive if levels get too high.  Fast growing plants that soak up the nitrates are your best defence against nitrate build ups.

Test your water on a regular basis as part of your routine and keep records of the results so that you can spot potential problems.  There are other times when you should look at testing as well.

• If you have more than one fish die for no reason, or you lose two or three fish over a few days.
• Your fish start behaving strangely or stop eating
• You have an outbreak of disease in the aquarium
• You have a power cut of three or more hours
• New fish die within a week
  

If in doubt test! 

If there is a problem, always do a partial water change on top of your regular maintenance.