Why Do I Have Ammonia Again??

I started fishless cycling my tank on March 6th using pure ammonia and some filter media from a friend's betta tank. On the 6th, I had 5ppm ammonia, and 0 Nitrite and Nitrate. By the 13th, I was getting 0 Ammonia after 24 hours and Nitrites off the charts. Since then, I've increased the ammonia to 3ppm every morning to feed the first set of bacteria. On the 22nd, Nitrites started to fall and Nitrates went off the charts. On the 28th and 29th, Nitrites hit 0, but Ammonia was at 1ppm after 24 hours. This morning's test was 0.25 Ammonia, 0 Nitrite.

What would cause my ammonia to go back up if it was 0ppm after 24 hours for a whole week? Will it possibly be fully cycled this weekend?

 

Two things - have you tested your tap water for ammonia? Not sure if you were doing water changes mid-cycle.

Second, have you tested your pH? Sometimes certain water can’t buffer the pH so the water goes very acidic and crashes your cycle.

Grab the pH reading if you can - might explain it.

 

We have well water. 0 for all readings. Ph is 7.8 for both the tap and tank.

 

I haven’t been doing any water changes. I’m going to do one or two large changes to get rid of the nitrates the day before I get my fish. Every morning I’ve been adding ammonia to get it to 3 ppm. Today my test was 2 ppm ammonia and 0 nitrate. I didn’t add more ammonia this morning.

 

It is possible to occasionally get a small ammonia reading in a fully cycled tank from time to time. As long as your ammonia doesn't go above .25 and nitrites are still 0 and your still getting nitrates.

Small ammonia spikes can be caused by a great many things. Try dosing to 2ppm and see if that goes down in 24 hours with no rise in nitrites. If that happens I would say your cycled.

 

I agree with Dave, and again I will say that biology is not a linear process.

It's sputters, it blooms, and it's subject to Natural things like water movement and air pressure and temperature, which are never All Uniform.

We might both have 20 gallon tanks that are exactly the same shape but they're going to come out different because of how we arrange things in them and what those things are and everything else around them.

Over time, and in general, everything Smooths out if you have a reasonable setup. But this is not a mathematical formula where 6 + 7 + 9 equals 22.

It's like having 10 numbers that you multiply together to get an answer, but each one of those numbers has only an approximate value.

You are never going to get exactly the same answer twice, with a million monkeys and a million years and a million fish tanks.


Also these tests are not 100%. Foolproof or accurate.

If I ever see some number that seems suspicious I will test again and more cautiously.

Finally, everything is quite temperature sensitive & a tank on one wall of the house will act differently than a tank on a different wall in the same room because of the thermal mass adjacent, and the local radiative, convective and conductive movements of energy.

Lord . . . I read that over & it sounds like Chinese feng shui. If you put tank on wrong wall, great Dragon of the East Moon will Slay Bacteria!

But it is true.

 

Haha!! Thanks for the feng shuI tip, Ulu!

Just realized that I turned down the heater a few days ago. That may have been my problem. It was at 82 and I turned it to 76. I’ll keep checking it throughout the week and see what happens.

 

They covered everything I could think of except, you didn’t clean your filter, did you?

 

They covered everything I could think of except, you didn’t clean your filter, did you?

Nope! The only thing that changed was the temperature. I guess it changed enough to kill off some of my bacteria.

 

Doubtful. 76 is fine to cycle a tank. It would take a bit longer at that low temperature, but lowering it from 82-76 wouldn't kill off the BB.