Beginner’s Guide to Fish Keeping and Building your first Aquarium (Part 2)

Adding fish

The last and probably most exciting part is adding your fish.

After your tank is completely ready and you figured out that you are going with the fish in cycling method and you’ve got your water in the tank, bio-media seeded, tank designed you are now ready to start adding a few fish to the tank to start your cycle.

As I said before Zebra Danios work well as a cycling fish as they are cheap and fairly tolerant of rising ammonia and nitrites. This doesn’t mean they won’t perish when levels go out of control, it just means they can weather the ups and downs a little better than other fish.

One tip here is not to over feed too much. for starting the cycle you can  feed  them  about double what they normally get but be careful not to over do it much past the first few feedings. Food that is better to cycle with is food that can break down into ammonia faster, so frozen blood worms or other frozen food like brine shrimp is a good start.

Zebra Danio (Female)

For the Two duration, every 3 – 4  days you should be doing a water quality check with your Fresh Water Aquarium Test Kit that you purchased.

After your cycle has taken hold in about 2 weeks (assuming you bought the liquid bio-additives I mentioned), I would add new fish species every 3 days or so.

New Tank Syndrome

Testing your Water for Ammonia, Nitrites,  Nitrates and PH will reveal how your tank is “doing” chemically. Testing is more important during periods of cycling such as setting up your new tank due to the effect known as “New Tank Syndrome”.

When first starting a tank, Ammonia concentrations in the water can rise dramatically within a couple of days creating a toxic effect to fish. This ammonia eventually gets broken down by bacteria in the water into Nitrite and subsequently by a different bacteria into Nitrate. When cycling a tank, your bacteria colonies may take time to cycle. Without using a good quality brand name liquid Bacteria product to help jumpstart this process, it normally take 8 – 9 weeks for these bacterium to build up in your tank and bio filter. In some occasions, the bacteria colonies do not propagate enough of the correct bacteria as well. Adding  a liquid bacteria product designed with the correct bacteria to do the job is highly recommended. It not only saves time but ensures a healthy stable aquarium environment.

Testing Your Water

Using your Aquarium Test Kit, You should follow the directions making sure to precisely measure the values.

Most test kits have a chart that you can compare color from your result to see where your tank is at during its cycle.

Typically I keep a Log during this process so that I can see the values rise and fall to watch to make sure the cycle is actually happening.

First you will get a big Ammonia spike, then it will start to taper off, and then a Nitrite spike, and then over time a gradual increase in Nitrates (this will not show if you live plants in the aquarium however as the plants will absorb most of the Nitrates.)

Ammonia and Nitrites are toxic to fish with Nitrite being the more toxic in higher levels.

Here you can see an API Fresh Water  Test Kit Results I took  awhile back when I had a little bit of  ammonia buildup in my tank:

API Test Results

As you can see,

PH is somewhere around the 7.6 range. PH scale is measure in Acidic  to Neutral to Alkaline. 6.0 would be very acidic, 7.0 neutral and 8.8  very alkaline.

Ammonia is reading somewhere in the 0.25 to 0.5 range. Ammonia is toxic to fish at all levels but starts to cause serious effects (and fatalities) in the 2.0 ppm range.

Nitrite (the Blue column) is very toxic to fish in any amounts however when cycling this value will go up a and down. As long as Nitrites keep under 0.5 ppm and go down quickly things should work out for the  better.

Nitrate although toxic to fish only in very high concentrations  (only some fish will react badly), Nitrate will generally increase over time  (only if you don’t have any plants in the tank eating it). It is a good indication that you need to change your tank water (10% water change) when this value starts to get high. Planting Live plants is a good idea because it can extend water changes. Plants also will use  ammonia for their processes so this reduces periods of ammonia spikes which although common can also cause your fish to be stressed for short periods.