# how many fish can i add after a fishless cycle?



## clekchau (Jul 24, 2011)

it should be finished in a week or two (hopefully)

i planned to eventually add 70 or so 2 to 3 inch growouts of a variety of species. should i phase this out into 40 or so the first time and wait a month and add the rest or so or can i add all at once?


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## jd lover (Mar 11, 2011)

never cycled but i herd with fishless you can add them all at once


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## clekchau (Jul 24, 2011)

does anyone know ? i'd hate to lose all those fish lol


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## Dominateprimate (Aug 27, 2011)

I usually add 5-10 fish at a time. but that's just me. (recommendation of my LFS)


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## clekchau (Jul 24, 2011)

but doesn't it depend on the size of the tank or number of fish you add? and how long do you wait before adding the next batch?


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## clekchau (Jul 24, 2011)

i guess the whole theory behind the fishless cycle is, if i add xx amount of ammonia, and in a few hours or so nitrites are at zero , the tank can handle that much bioload xx amount of ammonia will produce. i just don't know how to translate xx amount of ammonia to number of tish that woudl produce that waste equivalent and stock accordingly.

i hope i'm making sense :?


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## J.B. (Jul 14, 2007)

What size tank is this, and what filtration are you using?

You need to add fish slowly and allow the bacteria colony to grow with the new bio-load. As you add your fish, keep an eye on the NO2, NO3 and NH3 and keep up with your water changes _(30 - 50% weekly)_.

To be on the safe side, I'd wait a month in between additions to the tank.


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## jd lover (Mar 11, 2011)

http://cichlid-forum.com/articles/fishless_cycle.php

second paragraph under:

Advantages of fishless cycling over cycling with fish -or- Why should I bother with this?

states you can add all the fish at once


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## clekchau (Jul 24, 2011)

J.B. said:


> What size tank is this, and what filtration are you using?
> 
> You need to add fish slowly and allow the bacteria colony to grow with the new bio-load. As you add your fish, keep an eye on the NO2, NO3 and NH3 and keep up with your water changes _(30 - 50% weekly)_.
> 
> To be on the safe side, I'd wait a month in between additions to the tank.


Jb that would make sense if the colony was small but with the fishless cycle I built up the colony with the ammonia I put in to cycle the aquarium which establishes a large colony to begin with, enough to convert xxx amount of ammonia in a short period of time, at least from what I read.

It's a 600 gallon and filtration is a big wet dry with 15 gallons of bio balls. I'm all about being safe and patient but if I don't support the existing colony with enough waste to sustain it ie fish, the bacteria will die off. That's the reason you have to keep adding ammonia to sustain the nitrosomanes that convert the ammonia to nitrites. Am I missing something?


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## PfunMo (Jul 30, 2009)

One of the big points behind the fishless cycle is that you can add all the fish at the same time. The directions make that pretty plain, I think. Adding ammonia simulates adding a whole bunch of fish. If the bacteria handles the ammonia and nitrite as it should, It will handle the fish easily.


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## clekchau (Jul 24, 2011)

That's what I thought my main question would be how do I determine how many fish I could add, by the amount of ammonia that can be converted ?


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## DIAMOND_CICHLIDS (Sep 22, 2011)

Im off topic i know but id looove to see pictures of your 600g!!! :drooling: Hope you will post a few pics


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## halffrozen (Sep 24, 2011)

May have been covered before, but you should always add the most aggressive one last, and also it depends on the types of fish you are adding into the tank. As well as tank size and filtration.


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## dielikemoviestars (Oct 23, 2007)

You can add 70 at once if you've properly cycled the tank.


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## Dominateprimate (Aug 27, 2011)

I wouldn't necessarily say 70 but in a tank this size it would be a way larger number than I gave you before. Maybe 30-40 (40 being on the high end of things).


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## zimmy (Aug 13, 2010)

clekchau said:


> That's what I thought my main question would be how do I determine how many fish I could add, by the amount of ammonia that can be converted ?


To be on the safe side you could ensure your tank is processing a slightly higher dose of ammonia than typically used when fishless cycling. Most people are fine using 1-2 ppm ammonia when cycling. You might want to build up to 3 ppm. Having said that, 70 fish does not seem like a large bioload for a 600 gallon tank.

If your tank was smaller and the fish load being added correspondingly smaller, sticking with 1-2 ppm and just monitoring the tank once the fish are added (as you should anyway) would be fine. Worst case scenario would be that you'd need to do water changes for a couple of days while the BB catches up. Once BB is established it can multiply fairly quickly in response to the increased availability of nutrients (ammonia, nitrites). It wouldn't be fun changing water in a 600 gallon tank though so it might be better to have it ready to process more ammonia before adding the fish.


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## prov356 (Sep 20, 2006)

clekchau said:


> it should be finished in a week or two (hopefully)
> 
> i planned to eventually add 70 or so 2 to 3 inch growouts of a variety of species. should i phase this out into 40 or so the first time and wait a month and add the rest or so or can i add all at once?


As long as you've used 1-2ppm of ammonia to cycle, you can add a full load of juvies all at once with no problems at all. That's one of the benefits of fishless cycling. There's no reason to phase them in as with cycling with fish. Lots of good reasons not to llike aggression, cost if ordering online, etc.

Just wanted to add that once you add the fish, leave the system alone for 45-60 days or so, so you don't disrupt the bacteria. And keep water change amounts down to 25-30% or so, no more. In the early going there should be no reason to clean filters or get into massive water changes, particularly if stocking with juvies.


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## clekchau (Jul 24, 2011)

DIAMOND_CICHLIDS said:


> Im off topic i know but id looove to see pictures of your 600g!!! :drooling: Hope you will post a few pics


here are a few, still haven't put substrate or decorations


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## clekchau (Jul 24, 2011)

prov356 said:


> clekchau said:
> 
> 
> > it should be finished in a week or two (hopefully)
> ...


i hope i didn't do it wrong, i used 3 ppm and added more when nitrites were spiking and ammonia dropped to 1 ppm.... :?

also, are you indicating to only do small water changes to let the bacteria colony remain as stable as possible?


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## prov356 (Sep 20, 2006)

> i hope i didn't do it wrong, i used 3 ppm and added more when nitrites were spiking and ammonia dropped to 1 ppm....
> 
> also, are you indicating to only do small water changes to let the bacteria colony remain as stable as possible?


Lots of variations work. 3ppm will work, but it's more than you need, drives up nitrites, and ultimately nitrates and can extend the cycling time a bit.

I've seen large water changes cause some disruption to cycling and result in brief setbacks in the form of nitrite spikes once cycling is complete. Doesn't always happen, but others besides myself have seen it also. IME the best thing to do for a new tank is let it be and become an established tank.


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## clekchau (Jul 24, 2011)

prov356 said:


> > i hope i didn't do it wrong, i used 3 ppm and added more when nitrites were spiking and ammonia dropped to 1 ppm....
> >
> > also, are you indicating to only do small water changes to let the bacteria colony remain as stable as possible?
> 
> ...


thanks, so what is the next step now, just wait for the nitrites to come down and keep feeding ammonia when it gets below 1 ppm?

i have some seachem stability, should i start using that to speed it up or just let the cycle take its course? no water changes now?


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## prov356 (Sep 20, 2006)

> thanks, so what is the next step now, just wait for the nitrites to come down and keep feeding ammonia when it gets below 1 ppm?


Wait for ammonia to reach 0ppm, then dose 1-2ppm every 2-3 days. Ammonia should be 0 again after 24 hours. Do this untill nitrite reaches 0. You can do a small water changes to reduce nitrite levels. Daily, every couple days, not critical IME. I never do them when cycling.

As for Seachem Stability, can't hurt, but I've never used bacterial starters. I always use filter media from established tanks.


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## DIAMOND_CICHLIDS (Sep 22, 2011)

clekchau said:


> DIAMOND_CICHLIDS said:
> 
> 
> > Im off topic i know but id looove to see pictures of your 600g!!! :drooling: Hope you will post a few pics
> ...


This tank is so big, cant wait to see it finished! :thumb:


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## kamikaziechameleon (Oct 19, 2011)

I'm really funny about cycling. I typically over filter the **** out of my tanks and as such the bacteria cultures can expand and develop rapidly in my filters and clean more water etc. So I typically rush my tanks, up one day squeeze a old sponge filter into it then next day put fish in. maybe 2-3 per day or sometimes all at once. I haven't had a cycling issue in years. The thing is if you have carbon as I do when starting a tank it will absorb allot of the shock of the first cycle (assuming you have serious carbon) If you are starting from scratch and have no prior cultures to add to your tank then don't rush things. 2-4 weeks after setup add one fish, then a week in you can add 3 then another week you can fill her up.


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## prov356 (Sep 20, 2006)

> The thing is if you have carbon as I do when starting a tank it will absorb allot of the shock of the first cycle


Carbon doesn't do anything to remove ammonia or nitrite, so won't have any impact on cycling. Some mixes include an ammonia remover, but it's not carbon.



> So I typically rush my tanks, up one day squeeze a old sponge filter into it then next day put fish in. maybe 2-3 per day or sometimes all at once.


You've been lucky. Squeeze a sponge filter into a tank and fully load it with fish and 99% of the time you'll have serious ammonia and nitrite spikes and dead fish. Did you ever test for these, or just go by survival rate?


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