Quick cycling question

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

toddwcpa

Aquarium Advice Apprentice
Joined
Mar 8, 2016
Messages
22
One of my fish has been having babies and I would like to try and save some of the fry. So I bought a little 2.5 gallon tank and filled it with water from my current aquarium. Since the water came from my aquarium and I only have six tiny little fry, does this tank need to cycle? Also, what if I took some gravel and plants from the bigger aquarium? Would that help introduce more bacteria?
 
Your new tank and filter won't be cycled.

It will take a couple of months to cycle a tank, during which time you will need to be doing regular water changes if you have fish in there to maintain water parameters. This is called a fish in cycle. So yes, you will need to do a fish in cycle. The bioload of the fry will be low, so the amount of water you need to be changing to maintain water quality will be less than if you had the bioload of more developed fish, but your fry might need pristine water conditions. You might have grown out your fry to the point where you are considering moving them to a larger tank before your new fry tank cycles though. What type of fish is it?

Can you swap a little filter media from your main tanks filter into your new tanks filter? It doesn't take much to fill the filter on a 2.5 gallon tank, i do this regularly when i need to instantly cycle a small QT.

Will moving a little gravel help? Yes, a little bit. Not as much as moving some filter material though. Will moving a plant help? Yes, it will take up some ammonia and help out.
 
Thanks for the quick reply.

The fry are Boesemani rainbowfish and I only have six of them. They're so small they are very difficult even to see. Right now I have them in a fry net to protect them because there are cichlids in the tank too. I just thought I could take some aquarium water and move them to a separate tank. But not if I end up killing them in the process.

I did that once before with black convict cichlids and I had never even heard of cycling. That was before the internet existed. In fact, I just filled a 10 gallon tank with tap water and dumped about 50 baby convicts in there and they all did fine. Dumb but lucky, I guess.
 
Beneficial bacteria isnt really in the water. Well, it is, but not in any meaningful quantity. Beneficial bacteria lives on surfaces. The glass, substrate, any decorations, plants, but mostly your filter material. So transferring water won't do very much to help your cycle. Using tank water will of course mean you are moving the fry from identical water parameters and mean acclimating them shouldn't be an issue, so still worth doing.

Sorry i cant tell you how long your fry will take to grow out, and how long they should stay in your fry tank. Not a fish i have experience of.
 
I think I'm going to go ahead and move the fry over. Then, every few days, I'm going to remove some water and replace it with water from my established aquarium. If I keep doing this for a couple of months, it seems like it should work. I can't use the filter media because I'm using a tiny sponge filter in the fry tank and have a big canister filter in my other aquarium. But I can grab a couple of plants and some gravel. One thing I'm sure of is that they can't stay in that fry net long term. And it could take a long time for them to reach a size where I could safely transfer them back to the larger tank.

Thanks for you comments. Really appreciate being able to get a quick response on this site!
 
Once your fry are settled in their fry tank i wouldnt do water changes using water from your main tank. You are doing water changes to remove waste. Using water from your main tank will help bring down ammonia and nitrite becausei presume your main tank is cycled, but you will be adding nitrate in with every water change and so it will slowly build up.

Just use tank water for your first fill of your fry tank, but use clean water for subsequent water changes.
 
If you're able to move any sponges into the new filter (or just drop them into the tank) or move any lava rocks or wood from the cycled tank, it should atleast HELP!
I had to set up an emergency 3.5 gallon for inverts while treating their tank with something not invert safe. And I put some used sponges, a piece of wood, and some of the lava rocks and moss from my established tank into the 3.5 and everyone is still doing great and it's going on 3 months now! Lol. Almost dont want to move them back because they're doing so well!!
Anyways, best of luck to you!! :)
 
Back
Top Bottom