Question: Tank cycling, half way through?

I am in the process of cycling my tank. I am seeding good bacteria from a fully established pond (my fathers home pond), and i also have a heater in the tank to speed things up a little. It looks amazing and clear in there - but the amonia is at a dangerous level for any life in there. My axolotls are safe in a tub of water in the kitchen until their tank is ready. Regarding the cycling process, do i just leave it be and not change any water and one day the amonia will be at a zero level? I assume as the good bacteria grows, it will consume this amonia and the tank is fully "cycled". Is this correct? Its been cycline for only a week.
I have read that when heated and seeded, a tank can be fully cycled in 10 days. Its a 100 liter tank by the way.
Any advice would be appreciated. :happy:

I guess the question is "how high is high"? If the ammonia is super-high, it might be enough to kill the bacteria you are trying to cultivate. If it's over 5 ppm, you might want to do a partial water change. Whatever you added to the tank to generate ammonia, cut back on it. Also, how high is the temp?

I'm curious whether cycling the tank at a different temperature will work once the axolotls are added and the temperature is reduced. It's possible that different species of bacteria are effective at different temps, but I don't know.

its running between 27 and 30 degree's C. I read that the good bacteria take a long time to multuply in cold weather (its my winter here). Its looking a little cloudy in there today, so i might do a bit of a water change and give the pond water a break for a little while. The last ammonia rading was a day ago and it was reading 4.0 ppm. But it is creeping higher each day.

I actually had an issue with a stalled cycle and ended up removing my axolotls from the tank and putting in heaters and lights to warm the tank up. My tank finished the cycle in 5 days and has stayed that way since the cool-down and re-introduction of the axolotls. It worked really well for me, it seems that the temperature fluctuations didn't harm the bacteria.

wow! that is fast! How do you know when the tank is cycled?? i changed some of the tanks water today, and washed a portion of the filter wool. Its starting to look filthy in there - even with no axolotls in it! I am about to give up on it

I knew it was cycled when my ammonia levels were 0, my nitrite levels were 0, and nitrate existed in the tank. Cycling a tank just means that you build up the bacteria that "eat" certain chemicals in your tank. One type "eats" ammonia and one type "eats" nitrite. There isn't a type that "eats" nitrate, but if you include some live plants in your tank, the plants consume the nitrate.

My cycle really sped up once I increased the temperature in the tank and once I put in more "things" in the tank for the bacteria to grow on (rocks, plants, etc.). I would suggest to not do any water changes or to clean any filter media when the tank is in cycle as it could kill the bacteria that you are trying to grow. The majority of the bacteria will end up in your filter media, so washing it out during a cycle could damage the population of bacteria.

Some people may think that its alright to rinse out filter media, and I am by no means a professional, but if you do rinse your media, make sure its in tank water or dechlorinated water - that much I know to be true. You don't want to be killing the bacteria you worked so hard to grow with the chlorine is the water.

Your tank will start to look cloudy, and that's ok. The cloudy-white color is just a bacterial bloom. You know that you are doing something right when you see this.

Sorry that this post is on the long side. I was so clueless when I started cycling, so I just want to make sure I tell you everything that I learned. My tank took about 2 months to cycle halfway, but once I put the heater and lights into my tank, it finished off in 5 days. Just make sure to have a continuous supply of ammonia for the bacteria to consume and test your water for ammonia, nitrite, and nitrates frequently. I attached a picture of what you are doing in your tank. The diagram helped me understand the cycle.

Hopefully you don't give up! Your little monsters will thank you in the long run for being so patient with the cycle.

thanks for your advice. I'll keep up with the heat and checking of amonia etc. I have my axies in the kitchen, and i am just worried that they are not happy in their tub. They are still fighitng a fungil infection which they got from the tank and its high amonia. I did a very weak salt bath and their gills suffered big time. So now i just change the water 2 times a day to keep it clean for them.
So, even though the amonia level creeps up higher each day, it'll start getting lower one day???

What are you using as your ammonia source?

originally it was the amonia from the pond water i was seeding into the tank. But today i saw a fish pro and he sold me some little gold fish. I have 3 in there plus a live plant. It also has the plastic plants in there and river stones still.

lray said:

its running between 27 and 30 degree's C. I read that the good bacteria take a long time to multuply in cold weather (its my winter here). Its looking a little cloudy in there today, so i might do a bit of a water change and give the pond water a break for a little while. The last ammonia rading was a day ago and it was reading 4.0 ppm. But it is creeping higher each day.

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I suppose the general rule of thumb is that a reaction speeds up with heat. It would be interesting to see how quickly your tank cycles though.

Species of Nitrosomonas (metabolises ammonia) and Nitrobacter (metabolises nitrite), collectively known as nitrifying bacteria, are an interesting bunch. Just to touch on the temperature side of things, some tests have shown that the optimal temperature for growth is 25-30 degrees Celsius. Decreasing the temperature to 18 degrees Celsius will result in a 50% reduction in growth rate, whilst a 75% reduction in growth rate is noticeable at 8-10 degrees Celsius. Needless to say, no growth rate occurs at extremely low temperatures, i.e. <5 degrees Celsius.

I guess one thing you have to keep in mind if you decide to heat up the tank for quicker cycling is not to exceed the optimal temperature as anything at the higher end can also kill nitrifying bacteria. Also, it might be worthwhile keeping an eye on the nitrite level once when you do see a spike. Some tanks have been known to have a 're-appearance' of a nitrite spike despite the tank being completely cycled. Therefore, if you have lowered the temperature down to 18 degrees Celsius already, you may find the Nitrobacter having difficultly metabolising the nitrite as they are less resistant to lower temperatures.

Another thing would be dissolved oxygen (DO). There will be less oxygen in a heated tank. However, I don't know what the concentration of DO would be at a temperature for optimal growth. However, as nitrification is a metabolic process it will require oxygen and ATP. So, it might be handy to put in an airstone temporarily to maintain >80% saturation to achieve deseriable nitrification. The airstone can be removed once cycling is complete (but that's your choice).

lray said:

originally it was the amonia from the pond water i was seeding into the tank. But today i saw a fish pro and he sold me some little gold fish. I have 3 in there plus a live plant. It also has the plastic plants in there and river stones still.

Click to expand...

The problem I see with using goldfish is their high waste output. Considering your tank is already experiencing significant readings of ammonia, the goldfish will only compound to this issue. Also, you run the risk of not knowing whether the goldfish are harbouring any pathogens or diseases which may be transmitted to your axolotl. It's best to quarantine new stock for at least a month before introducing them to the tank. That is, of course, they don't exhibit signs of illness in which case you wouldn't introduce them to the tank.

P.S. Don't forget to check you pH, too! Good luck! :happy:

i will take your advice on borad You seem to know a lot. I have the tank running on about 27 degrees and i do have an air stone cranking out the oxygen. The goldfish are only tiny, and at this stage, i dont think i have anything to lose and am willing to try anything! But i did consider the possibility of transfering viruses to my axies. The fish do look very healthy and the guy who sold them to me assured me they were safe. His shops fish and axolotls were pretty impressive, so i do trust him. But like i said b4, you have given me some good tips above and i'll keep doing my research and reading and water testing in the mean time.