Fishless cycling

I started cycling for this system by using powdered ammonia. It worked pretty well. I wanted to share what my test kit looked like over the month.

This is what it started out looking like. Although nitrates and ammonia are flipped from how they will appear in the rest of the post.

So currently it shows test tube #1 PH is pretty high, above 7.6. Tube #2 nitrites are at 0. Tube #3 ammonia and tube #4 nitrates are both at 0.

Doing a little better now, PH is coming down ammonia is added, nitrites are still at 0

Ph looks good here about 7.2ppm. I over added ammonia, should have mixed it in a bucket and added it slowly rather than adding it directly, it took time for the ammonia to dissolve and mix fully. Nitrites is still at zero. At this point no reason to test for nitrates.

Hooray! First population of nitrifying bacteria are present. Due to the change the water becomes more acidic, Lowering the Ph. Tube #2 the ammonia is still really high, if I had fish in this would be a serious hazard. But tube #3 shows the presence of nitrites! This indicates nitrosomonas bacteria are present in enough quantity to convert ammonia to nitrites. Nitrates however at this point are at 0.

This shows that the ammonia is dropping and the nitrites are rising but still no detectable nitrates.

Finally the nitrates are rising! This can be seen by the last tube turning orange. Tube #3 is deepening purple showing a higher level of nitrites. With fish in the system this would have been toxic. You can also see that the Ph is still dropping, this can be buffered by adding builders lime.

After buffering with builders lime the Ph is back in normal range Tube #1. Ammonia is dropping in Tube #2. Nitrites are rising in Tube #3. And now in Tube #4 the nitrates are rising which indicates a healthy population of nitrobacter.

Here the nitrates in Tube #4 are dropping due to them being utilized by the plants as food. Ammonia in tube #2 is still high but there is no detectable nitrites in tube #3. I believe this is due do the Ph dropping too low which put the nitrosomonas bacteria into a hibernating state. Which you can see in the yellow color in tube #1.

Here you can see the nitrates in tube #4 are still rising and the ammonia in tube #2 are still dropping. There are still no detectable nitrites. But I don't believe that this means they weren't present but rather the being converted quickly to nitrates. Even at this low Ph the nitrobacter bacteria are still doing great.

Finally the system is fully cycled! Tube #1 the Ph is 6.8, Tube #2 the ammonia is almost to zero, Tube #3 nitrates are down to zero and the nitrates are high. (later finding my nitrate test kit is a little off, so they aren't quite as high as it looks)



2 thoughts on “Fishless cycling

  1. Awesome and informative!

    Do you have any rough estimates of time in between each picture? I’ve seemed to get the pH under control with some downer but my Ammonia has been a steady 7-8 over the last 5-6 days which I can’t seem to figure out how to drop…