Cycling question.

[Flowmsp]

Its been awhile since ive had to cycle a tank. Have had my fiances new tank up and running now for 3 weeks or so. Doing a fish "in" cycle, even though i would have liked to do fishless. Its a 30g hexagonal tank. Added some fake plants from my established 55 to get a start on the cycle. Atm after testing today ammonia was .25, nitrite0 and nitrate 5. Plan on doing a 40%wc after unless someone suggests not to? And Im assuming the nitrates are from the plants i had in there or uneaten food? There are only 2 zebra danios in there atm. Just kind of curious what time frame i am looking at here.

 

[lauraj]

There will be others much more experienced then I that will respond. In the meantime, a partial water change would not be a bad idea since you're at the upper limit of safe ammonia level for fish. Bringing plants from an established tank should help to speed up the cycle process a bit....not sure by how much though. It would help if you had some filter media from the other tank as well. I've been doing a cycle with fish without any jump from an established tank. I'm almost there, but it has taken 5 weeks fo far.

 

[FroggyFox]

.25 ppm is not 'at the upper limits of ammonia'. At this point I would not suggest a water change. I would wait until your ammonia or nitrite is up over at least 1ppm, or if its been a week since your last change. If its been a week then go ahead and do your 20-35% change.

If you have another tank setup you can take the filter media from that tank and just swish it in the new tank, that will help. (or if the tanks aren't in the same place you could squeeze some of the 'yucky stuff' into a baggie off of the filter in the established tank, and then pour that into the new tank's filter)

I just re-read your post, and 2 danios in a 30g tank is going to take forever to cycle, or rather may be a relatively invisible cycle because there arent enough fish to cause huge spikes. If I were you and you know what the tank is going to have in it eventually, I'd get maybe 1/3 of those fish (esp if you're getting more danios since they like to be in groups of like 6+, I'd get those) and then start using Stability combined with monitoring the levels and doing water changes, plus seeding from an established tank every few days...that would be great.

 

[lauraj]

I guess the upper limits of safe for ammonia is a matter of opinion. I've been told by experienced fish keepers that it's best for the fish to keep the ammonia at a max of .25.

 

[Big Vine]

Max. limit for a cycled tank = 0.
Max. limit for a cycling tank ~1.0 PPM (any more and a water-change is in order).

The ammonia needs to stay present in the water to a degree in order for the beneficial bacteria to thrive (i.e. not starve) and do their thing so that the cycle takes place.

BV

 

[lauraj]

Ah....that may be why it has taken me so long to cycle this tank! I believe it was the moderators at another site that tell all the new people to keep it at a max of .25.

Sorry for the misinformation, flowmsp. Although keep in mind if you're checking out other sites, you will get different, yet well meaning, information.

 

[Big Vine]

I've always had luck following these guidelines and doing what FroggyFox suggested earlier in the thread. All of this, of course, being in reference to 'fish-in' cycling of the tank.

BV

 

[Purple]

If all goes according to a "typical" cycle - expect to wait 6 to 8 weeks from scratch to complete. Adding established media (plants or filter gunk or substrate) speeds things up a bit - but then the timing depends entirely on the bacterial content of said media (eg unpredictable - but less than 6 weeks)

I'm not so sure that an ammonia reading of 0.25 would actually slow things down - but it would certainly mean your then cycled tank would have quite a small bacterial population (capacity to deal with small ammounts of ammonia only)

However, everything is relative, and danios are quite hardy when it comes to ammonia levels, so you could probably let it rise to 1.0 without unduly harming the fish you have in there.

So - basically - in your case 0.25 is good - so is 1.0

The key to cycling has always been patience - some tanks take months no matter what you try - some just seem to go a lot faster. My point is that your tank will cycle at its own speed - it's the fish keeper who needs to wait

Remember that once you have cycled the tank, it will only be set up right for the number of fish you have now - any additions should be done slowly. If you increase the population by 25% you have to wait for the bacteria to increase by 25% also (a week or so) so watch for spikes when you add fish.

Key phrase here is "don't rush things"

 

[Mountain Dewd]

I really admire people who actually set up and run through complete cycling before adding their fish. I have not yet had the full patience for it. I do however "borrow" the cycled filters from other established tanks and even on occassion put some of the gravel in a bowl and added that to the tank to speed things along.

Somehow, waiting for those bacteria to get going seems to take forever and in the meantime there are great fish to rescue from the LFS!