Wt? New Tank Cycling Faster Than Old Tank!

[navy]

I have 2 tanks cycling at the moment....

1 x 290 litre tank that has been cycling for 4.5 weeks and the Nitrite is only at .25
1 x 25 litre tank that has been cycling for 5 days and the Nitrite is at .50!!
Both tanks are cycling with a few hardy fish in them.

This obviously means that the 5 day old tank is cycling much faster then the other one! The only factors I can see for the 25 L tank are:
1. All the gravel in this tank was from a half cycled tank...however when I emptied the tank I washed the gravel throughly, so I doubt any bacteria survived since then.
2. I have put bottle bacteria in it (not that Bio Spira stuff) everyday.

Can this bottle cycle stuff actually work??? I mainly purchased it to see if it did work, as the guys at the LFS were all saying their tanks cycled within a week, which at this point I was saying to myself "hmm yeah RIGHT!". Maybe they weren't just making a quick sale after all......

Has anybody else got another explaination as to why this is happening?

 

[Miss Wiggle]

tanks do tend to vary the speed they cycle. i've never heard of any correlation between tank size, filter size etc in the speed of cycling. sometimes they just take longer than others!

 

[Squid]

How many fish do you have in each. You said "a few" in each. If they have the same amount of fish, then you will have a similar amount of ammonia production, which means that the ammount of ammonia and then nitrite will be more heavily diluted in a larger tank. Its a bit like you pee'ing in the sink or pee'ing in the sea..

Thats why if you do a fishless cycle, you bring the amount of ammonia up to 5ppm, which in a larger tank that was about 10 time bigger would need 10 times more ammonia to reach the same ppm....

Does that answer the question?

To see if the cycle products work, you would need to compare it with like for like conditions, including tank, filter substrate and ammonia introduction.

Cheers
Squid

 

[navy]

How many fish do you have in each. You said "a few" in each. If they have the same amount of fish, then you will have a similar amount of ammonia production, which means that the ammount of ammonia and then nitrite will be more heavily diluted in a larger tank. Its a bit like you pee'ing in the sink or pee'ing in the sea..

Thats why if you do a fishless cycle, you bring the amount of ammonia up to 5ppm, which in a larger tank that was about 10 time bigger would need 10 times more ammonia to reach the same ppm....

Does that answer the question?

To see if the cycle products work, you would need to compare it with like for like conditions, including tank, filter substrate and ammonia introduction.

Cheers
Squid

2 mollies in the 25 L
2 Mollies, 1 Mono, 1 Sucking fish (I think its called an Otto, its small) in the 290 L tank. So yeah there would be more pee in the 290 L tank

Yes I understand now, the bigger tank needs more ammonia, which it has, it has heaps more! While the little tank has very slight ammonia but has higher nitrite.

Thanks again Squid!

 

[xoedusk]

Could the nitrite in the 290 be falling, while the nitrite in the smaller one be falling?

I would expect at least some bacteria to survive the washing.

 

[navy]

Could the nitrite in the 290 be falling, while the nitrite in the smaller one be falling?

I would expect at least some bacteria to survive the washing.

Can you clarify this further? Do you mean to say you think the Nitrite in both tanks are falling? What washing? You mean water change? I'm confused lol