Transition from 'fishless cycle' to fish

[grahamu]

Hi,

In the past I have always cycled a new tank set up using fish. With this approach, as I have slowly built up the numbers of fish to my final population then, if performed correctly, the bacteria will build up in balance with the biological load.

However, for my first discus tank I am interested in using a 'fishless cycling' as described on this site.

My question is this. If the process is carried out as described, when the tank is fully cycled and the appropriate water changes carried out, what percentage of the maximum tank fish load should then be immediately added to the tank; 100%, 75%, 50%, 25%.

I assume it is important with such a cycling approach to match the fish load to bacteria load. Too many fish too soon and the biological process won`t be able to cope (like adding fish too fast in a fish cycle), too few fish and some of the bacteria will die off due to a lack of amonia feeding the process.

Thanks,
Graham

[ed8t]

I've fishless cycled 4 or 5 of my tanks this way and introduced a full load of fish each time. When I'm buying juvenile discus, I like to buy all my fish at once to keep them happy and comfortable.

If your filters can handle between 3 and 5 ppm ammonia and the resulting nitrites from that, that's way more than any full load of fish can ever produce. The nitrifying bacteria will die back to the levels produced by your tank inhabitants.

If you're performing lots of water changes, there shouldn't be much ammonia and nitrites for the filters to process either.

[grahamu]

Thank you ed8t - I appreciate your guidance.

Graham

[ed8t]

No worries - hardest parts about fishless cycling is finding a good source of ammonia and waiting for the nitrites to drop.

btw, welcome to the forum. Where were you planning on buying your fish? April (Pets Beautiful) brings in nice fish or special order.

[grahamu]

Thanks again ed8t - yes, eventually, I plan on giving April a visit.

That`s a long way off yet though; still need to finish all my research and reading on here, plan excatly what and how I am going to do my set up, get the equipment and cycle it.

The great thing on here is that as you do more research, it raises more questions (like the one I asked here) and if you can`t find the answer through searching then it is almost certain that someone will know the answer if you ask.

Cheers,
Graham