Help with Fishless Cycling

[azzajk]

hi i am cycling a 900L tank. i used dr tims bacteria and ammonium chloride for aa fishless cycle. dead rock and dead sand however some seeded media was used.

I am currently on day 21 and the timeline goes like this -

Day 1 - 13 i had ammonia
Day 14 i had 0 Ammonia but high nitrite
Day 21 still no ammonia and high nirtite

i test daily and nitrite is as approx 1
i even did a 50 percemt water change 3 days ago but no change to nitrite.

my 2 questions are -

1. does this all seem normal and should i do anything diferently?

2. there has been no ammonia for 7 days will the bacteria starve? should i be dosing ammonia?

 

[exnisstech]

Are you testing nitrates? Thats all I test for durring a cycle. If I see nitrates I pretty much consider it cycled. It doesn't hurt to make sure ammonia can be processed then very slowly start stocking.
Disclaimer I don't own an ammonia or nitrite test kit.

 

[Nano_Man]

Nitrate reading is good sign of cycled imo

 

[Gumbies R Us]

I would definitely check your nitrate levels

 

[jda]

You are probably OK.

Yes, bacteria can decline without ammonia/ammonium, and it does. It also can multiply quickly again.

Nitrite is not toxic to marine fish like it is in freshwater, but it is a sign that something is happening. There are also a lot of test kits that give bad readings. If you have some nitrate, then nitrite is getting processed. You probably have a bad test kit if the reading did not change after a water change. You are likely fine.

I would add a bit of ammonia again, make sure that the tanks stays at zero and then stop the ammonia once you get some fish, or a day or two before.

Just because you have some bacteria that can turn ammonia into nitrate does not mean that you have enough of them. Go slow, be smart and it will all be OK. Give those bacteria a chance to multiply.

BTW - the tank is ready for fish and you have some aerobic bacteria. It is not truly cycled. It will not be until the tank is super dynamic and respond to new fish, or some deaths, in a heartbeat that the aerobic part of the nitrogen cycle is complete - this can take a few months. Also, until it can complete the nitrogen cycle and turn no3 into nitrogen gas - this can take many months, or a year. The fully cycle does not stop at no2=no3 production. This is a good first step, but the term is misused by many and it is important to get it right so that when you read, or people help, then there is a baseline for communication.

 

[taricha]

i test daily and nitrite is as approx 1
i even did a 50 percemt water change 3 days ago but no change to nitrite.

my 2 questions are -

1. does this all seem normal and should i do anything diferently?

NO2 nitrite tests give a lot of color change for small amounts, so they are often saturated, or at least our ability to distinguish two strong dark colors is saturated.

Nothing unusual here. NO2 is just higher than you can easily distinguish with your kit.

 

[azzajk]

thanks for everyones responses

my nitrate is consistenly around 70 even after the large water change but unsure if thats skewed due to nitrite reading

is it worth putting a fish in and just assume nitrite will drop?

 

[Rmckoy]

If we go by the new cycle science it’s cycled .
but that’s not how I have ever cycled a system .

positive nitrates with no ammonia is the sure way to tell

 

[azzajk]

If we go by the new cycle science it’s cycled .
but that’s not how I have ever cycled a system .

positive nitrates with no ammonia is the sure way to tell

i do have 0 ammonia and reqlly high nitrate..

but akso high nitrite

do u think i can add a fish

 

[jda]

Nitrite jacks with nitrate test kits. I would wait for the no2 to come down a bit to be in the error range of the test kit and to where there is no interference with the no3. There is no such thing as new and old cycling... biology and chemistry have not changed in our lifetimes. No harm to wait.

 

[azzajk]

Nitrite jacks with nitrate test kits. I would wait for the no2 to come down a bit to be in the error range of the test kit and to where there is no interference with the no3. There is no such thing as new and old cycling... biology and chemistry have not changed in our lifetimes. No harm to wait.

But should I add more ammonia so the bacteria can feed? It’s been a week with no ammonia

 

[Rmckoy]

i do have 0 ammonia and reqlly high nitrate..

but akso high nitrite

do u think i can add a fish

As mentioned above nitrite will contribute to the higher nitrate results .
Nitrite is less toxic in saltwater but I would personally wait .
Nothing good happens fast in this hobby .
there is no harm in waiting .

to be sure your cycle is finished you can add a small ammonia source to test how fast your system can process the amount dosed .