Adding Fish After Fishless Cycle

[scouse_andy]

My tank is part way through a fishless cycle and I am finally settled on my stocking plans.

I would like to add all of the fish in a short space of time, like 2-3 days at the end of the cycle (they are mainly juveniles so would not be anywhere near the max bioload of the tank as most have lots of growing to do).

Is this a sensible thing to do? I know that it is recommended for mbuna tanks so all the cichlids can start from the same point rather re-establishing pecking order etc.

The reason I ask is that an experienced fishkeeper, who has never done fishless cycles and is passing on some geophagus to me, feels I ought to wait a while before adding the geos.

In a lot of caresheets for species you see things like "should only be added to an extablished tank" etc. Is there anything that a tank which has been properly fishlessly cycled doesn't have that a mature 6 month old setup does have or am I really good to go (as I suspect)?

I would hate to buy all my stocking and find that some of it struggles or worse because I really ought to have waited.

 

[mattlee]

a fishless cycle if done at 4-5ppm should be more than enough to cope with any bioload so i would add them all at once and use it as a quarentine tank at the same time. i dosed my tank to 4-5ppm and added a full stocking of adult cichlids including a 12 inch oscar and catfish without a rise in ammonia or nitrite levels

the longer you leave the tank with a small bioload in the more risk you will have when adding new fish at a later date as the bacteria will die off to the amount neede to cope with the stocking at the time.

an established tank really is a tank thats been set up for a while and all levels are steady like pH etc etc as long as you keep an eye on the water for the first month then you should have no issues at all.

if they are juvis then their bioload will be tiny so dont worry

 

[scouse_andy]

Good, that's what I fully expected to hear but thought I would run it past people on here first.

It does seem a bit daft to get your filter to a point where it can handle 4-5ppm of ammonia and then allow three quarters or more of the bacteria to die off because you only add a handful of fish to start with.