cycling a new tank

[bensmom2000]

Hi all!

I am upgrading my betta from a 3.5 gallon to a 20 gallon tank! very exciting

I am wondering how long it will take to cycle the new tank so I can put my little guy in there. I used a water conditioner on all the new water, and added about 2 gallons of water from the old tank. How long do you recommend I cycle the tank before putting him in?

Thanks!

 

[Aiken Drum]

Are you planning on cycling the tank with fish in it, or cycling the tank before you add fish?

A fish in cycle, you can add your fish straight away.

A fishless cycle normally takes 4 to 6 weeks, and can take longer.

A fish in cycle basically involves daily water tests and water changes to control the waste (ammonia + nitrite), until you have cycled the tank and the beneficial bacteria can process out the waste.

A fishless cycle involves replicating fish waste by adding ammonia so the beneficial bacteria can grow sufficiently so your tank is cycled before you add fish.

You speed up the cycle process in both methods by adding some filter media from an already established filter. Simply adding water from your established tank won't do very much.

 

[Aiken Drum]

Ill add something to my previous post.

20g is a big tank for a betta.

I assume you are planning on including some other fish. If so, introduce your betta after whatever else you plan to stock has been introduced. You dont want your betta to have set up its territory within the tank and then have it upset by new tank mates. The space available in a 20g will reduce this risk, but better safe than sorry.

If you are planning on just the betta, the waste produced by a single fish in such a large volume of water will be negligible. If so, just introduce your betta, and do a fish in cycle. This should be a painless method given the low bioload and the benefits of the larger tank will outweigh any stress of moving it. If you can move some, or all, of your filter media to your new filter, you might not even need to cycle at all.

 

[charliebankston]

Ill add something to my previous post.

20g is a big tank for a betta.

I assume you are planning on including some other fish. If so, introduce your betta after whatever else you plan to stock has been introduced. You dont want your betta to have set up its territory within the tank and then have it upset by new tank mates. The space available in a 20g will reduce this risk, but better safe than sorry.

If you are planning on just the betta, the waste produced by a single fish in such a large volume of water will be negligible. If so, just introduce your betta, and do a fish in cycle. This should be a painless method given the low bioload and the benefits of the larger tank will outweigh any stress of moving it. If you can move some, or all, of your filter media to your new filter, you might not even need to cycle at all.

Correct me if I'm wrong Aiken, but it's possible that 1 small fish in there will actually never cycle the tank anyway

 

[Aiken Drum]

I suppose it depends on what you mean by cycled.

- If you did your weekly water changes, it might be that you never see detectable ammonia, nitrite or nitrate because of the low bioload and regular water changes. In this circumstance there might not be enough ammonia to develop beneficial bacteria.
- If you did water changes less frequently, to the point where you do get detectable ammonia, then it should develop some beneficial bacteria to the point where it will process waste sufficient for the single fish and frequency and size of water changes.

Either way, if the water is safe for fish i would consider it cycled for the current stocking. It doesnt matter how you get to safe water parameters, water changes, beneficial bacteria, action from plants, it all achieves the same end result.

If you wanted to put in the single fish, leave it for a few weeks, then add a dozen neon tetras, your tank wont be cycled for the higher bioload, and you would need to then go through a fish in cycle process.

Correct me if I'm wrong Aiken, but it's possible that 1 small fish in there will actually never cycle the tank anyway

 

[bensmom2000]

I suppose it depends on what you mean by cycled.

- If you did your weekly water changes, it might be that you never see detectable ammonia, nitrite or nitrate because of the low bioload and regular water changes. In this circumstance there might not be enough ammonia to develop beneficial bacteria.
- If you did water changes less frequently, to the point where you do get detectable ammonia, then it should develop some beneficial bacteria to the point where it will process waste sufficient for the single fish and frequency and size of water changes.

Either way, if the water is safe for fish i would consider it cycled for the current stocking. It doesnt matter how you get to safe water parameters, water changes, beneficial bacteria, action from plants, it all achieves the same end result.

If you wanted to put in the single fish, leave it for a few weeks, then add a dozen neon tetras, your tank wont be cycled for the higher bioload, and you would need to then go through a fish in cycle process.

I just got some corys and neon tetras that are currently hanging in the old tank which is now quarantine. I do already have my betta in the 20 gallon (I plan on taking him out to introduce his tankmates) The tank has been good for just my betta and mystery snail, I used the filter cartridges from the old tank and some decorations and plants as well, and so far all water tests have come out good. But, you mentioned the tank will not be cycled enough for the higher bioload. Is there any way I can prep the tank for them beforehand or is the fish in cycle the best way to go?

 

[Aiken Drum]

I just got some corys and neon tetras that are currently hanging in the old tank which is now quarantine. I do already have my betta in the 20 gallon (I plan on taking him out to introduce his tankmates) The tank has been good for just my betta and mystery snail, I used the filter cartridges from the old tank and some decorations and plants as well, and so far all water tests have come out good. But, you mentioned the tank will not be cycled enough for the higher bioload. Is there any way I can prep the tank for them beforehand or is the fish in cycle the best way to go?

Yes. You could do a fishless cycle, which would cycle the tank before you add fish. This typically takes 4 to 6 weeks. However as you already have your fish, i would go fish in. Your 3.5 gallon isnt really big enough to hold all those fish while you cycle the 20g.

Fishless cycle guide link if you are interested in the process.

https://www.aquariumadvice.com/tips-and-tricks-for-your-fastest-fishless-cycle/

Do you need advice on fish in cycle?

 

[bensmom2000]

Yes. You could do a fishless cycle, which would cycle the tank before you add fish. This typically takes 4 to 6 weeks. However as you already have your fish, i would go fish in. Your 3.5 gallon isnt really big enough to hold all those fish while you cycle the 20g.

Fishless cycle guide link if you are interested in the process.

https://www.aquariumadvice.com/tips-and-tricks-for-your-fastest-fishless-cycle/

Do you need advice on fish in cycle?

I do know how to do it, but if you have any tips or tricks I'd appreciate it!

 

[Aiken Drum]

Feed sparingly. Say half the amount of food you normally would feed, or only feed every other day.

Water test every day. If your ammonia + nitrite combined is above 0.5ppm then do 25% water test. If your water parameters get out of hand and they rise above 1ppm combined, then do 50% water change or 2 x 30% water changes a few hours apart.

I would be doing this for both your new 20g and the 3.5g tank you are using as a QT. The 3.5g is now quite heavily stocked and you could get some spikes.

When you are consistently seeing 0ppm ammonia and nitrite (say everyday for a week) and your nitrate is steadily rising, then you are cycled for your current stocking and you can add some more fish. I wouldnt add more than an additional 25% stocking in one go. Rinse and repeat until you are fully stocked.