Best Way to Prepare New Tank When Up sizing Aquarium

Hello

I'm about to upside from a 40L to a 76L aquarium.

I'm not sure whether it's best to prepare by seeding the new tank by adding the filter & maybe the gravel from my old tank.

Or to Cycle the new tank from scratch - in which case I'd attempt the fishless method using ammonia.

Any advice and tips on other important factors considered would be much appreciated.

 

Easiest way is to just transfer substrate, water and fish, put your existing filter media into the new filter, switch on and you're done. There's no need to cycle, or seed the new filter.... unless you want to keep the smaller tank running aswell.

 

What hampalong said is easiest. I would probably cycle the new tank with ammonia, but that is just because I want the experience. Hehe.

 

If you are upgrading to a larger filter and choose the seeded route, add some extra media to the smaller tank now and put that inside the larger filter when you upgrade. It can simply be placed inside the aquarium if you don't have room in the smaller filter.
Alternatively, you could run both on the smaller aquarium IF your fish won't mind the extra water flow.
Then run both on the larger tank for a while until the bb in the new larger filter gains some momentum.

Edited to add: I like this method to keep the smaller filter cycled for the smaller aquarium if you plan to keep both active.

 

Thanks for the great advice - I chose the seeded route.
Placed the sponge and Biomedia cartridges from my new Fluval U2 filter into my old aquarium this morning.
How many days should it take for the seeding of the new bacterial colony to be sufficient to start the new aquarium?
I'll be putting my existing 3 danios in at that point.. How long do you think I should then wait to start gradually. increasing the fish population.

 

If you didn't add any used media to the new filter, it can honestly take up to a couple weeks.
If you add some of the old filters media, 2-7 days depending on how much you added and the bioload the old filter was capable of processing. A small amount will be sufficient after a few days to start cycling the new tank with 3 danios.

 

Thanks again Maeve Was hoping that by submerging ALL of the media from my new filter in the old aquarium for a period, I'd avoid much if not all of any ammonia or nitrate spikes.
The differences in filter design make it impractical to insert the old filters media into the body of the new filter.
BUT I do plan to run the old filter alongside the new one for a few weeks as well.
My surviving 3 danios have already endured one tank cycling. So I wanted it to be easier on them this time

 

Thanks again Maeve Was hoping that by submerging ALL of the media from my new filter in the old aquarium for a period, I'd avoid much if not all of any ammonia or nitrate spikes.
The differences in filter design make it impractical to insert the old filters media into the body of the new filter.
BUT I do plan to run the old filter alongside the new one for a few weeks as well.
My surviving 3 danios have already endured one tank cycling. So I wanted it to be easier on them this time

Good plan and I think I heard them say ty!

 

If you are upgrading to a larger filter and choose the seeded route, add some extra media to the smaller tank now and put that inside the larger filter when you upgrade. It can simply be placed inside the aquarium if you don't have room in the smaller filter.
Alternatively, you could run both on the smaller aquarium IF your fish won't mind the extra water flow.
Then run both on the larger tank for a while until the bb in the new larger filter gains some momentum.

Edited to add: I like this method to keep the smaller filter cycled for the smaller aquarium if you plan to keep both active.

I've been wondering about this myself because I'm hoping to have a larger tank up and running over the next couple months. I don't have any of the parts to it yet, but I wanted to ask to make sure I'm understanding correctly.

I could take the media from a new filter and place it somewhere inside my smaller tank if it doesn't fit in the smaller filter? And how long would that need to sit inside the smaller aquarium to build an appropriate amount of BB? Could it be attached with a rubber band around the intake of the smaller filter until time to place into the new filter? Or would that be too rough on it?

And would it be beneficial to place additional driftwood that I plan on placing in the new tank into the smaller tank beforehand for the same purpose? Or if it comes from a mostly-trusted LFS aquarium, would it have enough BB on it to be of any use in the new aquarium?

 

I just got some ready in two weeks leaving it in the corner of the tank with the least water flow. I didn't vac around or under it for that whole time. Fish waste is what drives the bacterial growth. Watch your nitrates when leaving waste in the tank on purpose.

Driftwood isn't going to collect enough to be of much use. You want porous media like sponges or bio balls. Lava rocks work too, but it's so much easier to see white media gain a brown tint.

You want to treat seeded cycling the same way you would fish in cycling and add new fish slowly, and wait a week after upgrading to do so. Seeded media can only handle the bioload it grew to, and most of that BB is still on the old filter. It's common to see a trace of ammonia for a few days to a week as well. Testing daily and dosing prime/doing water changes as needed are just as necessary as with fish in.