How many fish to start with?

[kwl718]

I'm new to fish altogether. I've been fishless cycling a 15 gallon for my four year old for five weeks..ugh, but we're finally getting there. The ammonia eating guys got right on things and have been gobbling up 2ppm of ammonia a day for 4 weeks. It stalled on the nitrites, 5ppm+ and 5ppm nitrates (my tap water has 5ppm nitrates) for more than three weeks. Last weekend, I changed out 80% of the water two days in a row, skipped ammonia for a day to give the nitrite eating guys a break, re-dosed ammonia to make sure that the ammonia guys made it and then put in some bio-spira and went back to regular dosing..this time 1/2 in the morning 1/2 in the evening rather than all once a day. The ammonia eaters made it through the water changes with no trouble and I waited a day after making sure they were on the job and ammonia and nitrite were 0 and low before adding the bio spira...I didn't want high levels to kill the bacteria in it. Nitrites rose back to 5ppm within a couple of days, but have now dropped to 1ppm and the nitrates have finally climbed to 20ppm. I don't think it will be too much longer!

So, anyway, assuming we'll be able to get some fish within the next week or two, how many can go in at once? The tank is eating up 2ppm worth of ammonia a day (I know how much ammonia to add to get there), I dose 1/2 in the morning and 1/2 in the evening, so it's probably not over 1ppm at any given time, it's always at 0 12 hours after a dose. I'm keeping it at this level and waiting for the nitrite eaters to catch up. So, once they, do and I make sure they hang in there for a week of continued dosing..big water change to get rid of nitrates, lower temp from 85 and find some fish.

My son is interested in zebra danios and some corys. How many should I put in initially? I don't want them to produce more ammonia than the tank can handle, but I'd hate to have much of my hard earned bacteria die back because I under stock it dramatically at the beginning. Or, does that even matter? Even if the fish make nowhere near 2ppm of ammonia a day and some dies back, will having an established colony in there, even a small one, make it easier to add more fish as time goes on?

[Marinemom]

First of all, keep on monitoring the water conditions. The ammonia and the nitrites both need to be sitting at 0 and you need to see some nitrates before you are fully cycled. My concern is that you said you added bio-spira and you are doing a fishless cycle. If I am not mistaken, the bio-spira should be used at the same time that you add the fish and it speeds up the cycling process for you all the while keeping your fish safe from toxins in the water. Do you have any fish or shrimp or anything living in the tank right now to feed the bacteria and build up the nitrifying bacteria needed to support the life in the aquarium? I am a little confused here.

As far as the fish are concerned, when you are done cycling it will be safe to add a FEW fish. It is important to go slow so the filter has a chance to play catch up with the new bio-load in the tank. This should take at most a few days. Most people will add a few fish every two weeks or so until you have the amount of fish you want in the tank. This also insures that in that time frame you can watch to see if any problems arise with the new fish such as disease. Then of course you will act accordingly with treatment and whatever else is necessary to insure the health of your fish.

Good luck with the new setup. I hope this helps.

Marinemom

[kwl718]

Thanks! Yeah, I know that bio-spira is usually used to avoid doing any cycle, but, frankly, I just couldn't go on blind faith like that! I used it to try to get out of the nitrite stall by introducing some bacteria from somewhere, it seems to have helped..or maybe it was coincidence and the nitrite eaters were about to start growing anyway and I wasted money. I have no one to borrow tank media from...everyone I know with fish doesn't keep a particularly healthy tank, they are just winging it and have fish die regularly.

There are no fish or other living things in the tank, I've been dosing with plain ammonia every day for all this time.

My plan is to wait until nitrites are at 0 (ammonia has been returning to 0 every day for weeks) and stay there for a week, through continued ammonia dosing, before adding any fish.

I'm in no hurry to add lots of fish, but was wondering if I'd lose much of my 2ppm/day bacteria colony when I stop the manual ammonia dosing and rely on just a couple of little fish...though it might not even matter, if the colony will grow promptly as I add more.

[Marinemom]

The bacteria needed to support the life that is in the aquarium will be taken care of by the fish. When you add more fish then the filter will play catch up and produce enough for the new load of fish. I wouldn't worry about adding ammonia after you add the fish. Who wants to keep doing that anyways? The bacteria at the point will be growing very quickly so I think you will not have to worry about it.

Marinemom