Zebra danios always the cycle starter??

[optix]

Im just curious as to why these are the fish that everyone uses to naturally start the biological cycling of the aquarium. Are they like bullet proof or something??

[Cearbhaill]

Not bulletproof- just always available at low prices and tolerant of a wide variety of water conditions.
Lot's of folk like Zebras and choose them for their coloration and activity level alone. I find them too hyperactive, but ymmv.

[ChilDawg]

They are pretty hardy, but I've never tried shooting one, so I cannot answer to whether or not they are bulletproof. However, as Cearbhaill said, they are cheap and tolerant of all sorts of water conditions--the only problem is their propensity to nip fins and the fact that their "zip zip zoom" style of movement will scare inactive, shy fish. Thus they are not perfect for cycling an Angel or Discus tank--unless you have somewhere else to put them afterward.

[ChilDawg]

Note: I still recommend fishless cycling.

[wetmanNY]

When "hardy" fish are stressed with a month of fluctuating ammonia and nitrite levels, they initially survive. So we call them "bulletproof." Months later, when they swell with retained fluids because their liver is shot, we call it "dropsy" --and we don't make a connection.

There's fishless cycling. And now there's Bio-Spira. Maybe, if you want to cycle using fish, you should use Bio Spira. The next time I set up a raw tank for someone, I'll use Bio Spira: I want to see how the stuff works for myself.

[ChilDawg]

With what fish would you cycle the tank using Bio-Spira WetmanNY? Or would you stay away from fishy cycling and let the Bio-Spira grow on its own?

[ChilDawg]

I take that second part back--it looks as though you almost have to put the fish in right away or else the bacteria don't work properly.

[wetmanNY]

Right! that's what the directions say. If the product is working as advertised, you put a light fishload in right away.

When I use this new stuff to cycle a raw tank, I wouldn't start with "delicate" fish like Cardinal tetras or Rams.

...so am I just falling into the same kind of "hardy fish" thinking, after all?

[ChilDawg]

It really depends at that point--if you are counting on the stuff not working, then, yes, I would see you falling into the same line of thinking. If you are counting on it working, then you'd be wise to start with less delicate fish and then move to the more delicate ones as you see it working more and more.

I might test it for the next tank that I do (besides the one which has already cycled at home), but I will start with Danios and such under the assumption that the stuff doesn't work.

Then I would move toward more and more delicate fish, but definitely not Cardinals until there are some well-controlled studies published by legitimate sources. (I don't count myself as legitimate for those purposes, but I would count you, RTR, or a number of other people to be legitimate sources.)

[ScottoMacD]

I always use barbs (usually golden) to cycle. They last for years afterward. Unless of course I decide to let them go for a swim in the big boys tank. Then they don't usually last that long.

[Kirin Fang]

I've had luck with cycling with Tiger Barbs, but I use fishless cycling now.