# Cycling a planted tank



## Fishflake (Apr 23, 2010)

*Help me understand*

I'm in the process of cycling (fishless) a planted tank. I've cycled tanks before, but never planted tanks. The cycle is at the point where I add ammonia to 3-4 ppm and in 24 hours it's at .25ppm. So I'm thinking that I'm 1-2 days away from getting a 0 ppm reading after 24 hours. Out of curiosity I did a Nitrite test. Nitrites are at 0 ppm. So I then did a Nitrate test and they are at 5 ppm.

Being new to planted tanks, my best guess is as follows: There are two processes going on here. The biofilter is developing as usual, but because I have a heavily planted tank, the plants are consuming the ammonia (ammonium?) as well. Some ammonia is being converted to Nitrite because Nitrate is present. All Nitrite is being converted or consumed.

Does this sound like a plausible explanation?

Also, I'm thinking that when I show 0 ppm for Ammonia and Nitrite after 24 hrs of adding Ammonia that I'm good to add fish.

Thanks

TANK INFO:

40g with 20g sump
Ecocomplete substrate
Day 21 of cycle. Seeded with filter media from established tank
78 degrees
2 x 39 watt T5 bulbs
Flourish 1 x per week per bottle instructions
Heavily planted. Plants growing well
No CO2


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## Fishflake (Apr 23, 2010)

I posted this in the "el natural" forum but got no response. I'm hoping someone here will share insights, opinions, experience. Thanks.

I'm in the process of cycling (fishless) a planted tank. I've cycled tanks before, but never planted tanks. The cycle is at the point where I add ammonia to 3-4 ppm and in 24 hours it's at .25ppm. So I'm thinking that I'm 1-2 days away from getting a 0 ppm reading after 24 hours. Out of curiosity I did a Nitrite test. Nitrites are at 0 ppm. So I then did a Nitrate test and they are at 5 ppm. 

Being new to planted tanks, my best guess is as follows: There are two processes going on here. The biofilter is developing as usual, but because I have a heavily planted tank, the plants are consuming the ammonia (ammonium?) as well. Some ammonia is being converted to Nitrite because Nitrate is present. All Nitrite is being converted or consumed. 

Does this sound like a plausible explanation?

Also, I'm thinking that when I show 0 ppm for Ammonia and Nitrite after 24 hrs of adding Ammonia that I'm good to add fish.

Thanks

TANK INFO:

40g with 20g sump
Ecocomplete substrate
Day 21 of cycle. Seeded with filter media from established tank
78 degrees
2 x 39 watt T5 bulbs
Flourish 1 x per week per bottle instructions
Heavily planted. Plants growing well
No CO2
KH: 5
GH: 4
Ph: 7.8
Ph


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## Michael (Jul 20, 2010)

*Re: Help me understand*

I would say yes to both questions.

Did you use any soil, or just 100% Ecocomplete? If you used soil, you do not need to add ammonia to cycle the tank; the ammonia would come from the soil.


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## jdigiorgio (Jan 29, 2004)

How long has the tank been set up?

Did you ever have your ammonia and nitirte spikes?

Cycling a tank should take between 3 and 5 weeks. You have to make sure that you initially had your ammonia and nitirite spikes.

If you did have them, I would say you are good to go.

My tank has been set up for almost 9 weeks and I am still getting .25ppm of nitrites. I have a small bio load with only 12 rams in a 125gallon tank. So it could take longer.


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## sandeepraghuvanshi (Feb 22, 2007)

Well, I had typed out my reply in your eariler post but got disconnected from internet.
So here I go again.
Nitrogen cycle in a tank requires presence of ammonia, this gives rise to bacteria that convert ammonia to nitrites and subsequently to nitrates.
Now plants are said to prefer Nitrogen in form of Ammonia often nitrates, and will absorb ammonia as long as it is available in water.
Hence they directly compete with nitrifying bacteria for ammonia and hence it is often said that Nitrogen cycle will never even start in a well planted tank.
Hence I fully agree with your observation.
You can safely introduce fish in this tank.
In a non planted/less planted tank the usual assumptions of nitrogen cycle will apply.


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## Michael (Jul 20, 2010)

Actually, you did get a response in El Natural. I have merged the threads so that all responses are in the same thread.


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## Fishflake (Apr 23, 2010)

Thanks for merging the threads. And thanks for all responses. I'll be ordering fish soon as ammonia is now 0 ppm.


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## Diana K (Dec 20, 2007)

Cycling a well planted tank is different, in the way you figured out. As the plants get established they remove most of the ammonia, nitrite and nitrate. 
But not all. The bacteria grow a bit slower, since the plants are getting most of the ammonia, but they do grow. Also, there are likely a lot of bacteria introduced to the tank on the leaves of the plants. 
This sort of cycle might go as fast as a few days or a week. 

As soon as the tests show the water is safe, go ahead and stock the tank. With both plants and bacteria there is plenty of bio-filter.


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