Fishless Cycle

[SandraNewbie]

so I have access to a biology lab and I'm helping set up a couple of tanks. From this lab I can get, very cheaply, both ammonia and urea.

for the ammonia it appears to be 100% ammonia with trace (ie 0.0X %) impurities. And the urea is pure.

Which of these and how much of these should I use to establish filter bacteria.

Also, the gentleman who's tank it is has connected the new filter in to an old tank (it's a filter for a 300L tank on a 100L tank on top of its original filters), will this promote bacterial growth? When he removes this filter, will it crash the bacterial filtration for the 100L tank?

 

[SandraNewbie]

Have just found your article on fishless cycle and spotted the instructions call for about 3ppm. I'll go with that and use the ammonia rather than the urea.

I've also seen some things saying that going up towards 6ppm if you want to stock the tank more fully from the beginning but I'm assuming this comes from impatience?

 

[Gvilleguy]

Hi Sandra,

Just to verify, the new filter has been connected to, and running on, an existing tank that already has cycled filters running on it? I'm not sure how helpful that will be. Have never tried it. What is more common is to take a portion of the media inside a cycled filter and place it in your new filter. This immediately gives you some established bacteria that can grow onto the new media.

Regarding ammonia concentration for cycling, 3 ppm is probably sufficient for the tank load. I've heard different preferences from different people.

My own preference is to go with 4 ppm ammonia for the first phase of the cycling, and then once you enter the nitrite phase, ease off the ammonia top offs to 2-3 ppm.

The "do and do not" thread linked in my signature also answers additional questions not handled in the beginner's section.

 

[phantomlink]

Also, that ammonia of yours, if it IS actually 100% you only need 0.3ml to get your 3ppm so... be careful with that

 

[waterdrop]

Agree with GVG. The gentleman can "donate" up to 1/3 of the media from one of his filters and it should have little to no effect on the ongoing biofiltration of his existing tank. Taking a donation of media like this is much, much more effective than having a new filter run on an old tank (if indeed running a new filter on an old tank is effective at all - it would take weeks to be significant in my opinion.)

The way to go about it is to obtain fresh media that you give him to plug the area which he takes out to put in your filter (a chunk of sponge for instance.) Put the donated media into the water path inside the filter right before the new media (ie. the water passes through the old muddy media first and then straight into your new media - you may have to be creative with scissors or something to do this but it is extremely effective. This effort will result in great time savings usually over a pure fishless cycle but it is still desirable for a beginner to perform a fishless cycle on this filter because of all the learning that goes on in this process.

~~waterdrop~~

 

[SandraNewbie]

Aaah right, we've squeezed the filter sponges out into the new filter, but we've not moved any sponge. I'll do that when I get back on thursday. I'm not over worried about rushing the cycle, This tank could take 8 or so weeks and it wouldn't be an issue.

As for the 0.3mm I think you may have done the maths wrong. On the 300L tank that we're cycling to, 0.3ml is 1ppm, so 1 - 1.5ml would be 3-5ppm. (getting that accurate will be tricky business, especially when it comes to topping up but the boy's a biologist, he'll "borrow" a pipette or something I'm sure.