Tank Upgrade - Cycling from Old Tank

[Rin2809]

We are upgrading from a 5 gallon tank to a 20 gallon tank. Our plan is to move the 2 guppies and 3-4 ghost shrimp, along with most of the decor over to the new tank (while adding some new), completely taking down the 5 gallon. Then once we are established, add some new residents to the tank.

Rather than start a full cycle from the beginning, can I transfer the water from our 5 gallon into the new tank and treat is like a really big water change? Will the nitrogen/bacteria levels from my old tank be enough to skip the normal cycling process? It would be ideal for us space-wise not to need to have both set up for too long and I thought I remembered from way back when I set the 5 gallon up 2 years ago that this was an option to speed up cycling.

 

[claudio1]

hi,i did a similar tank upgrade last year and i was succesfull or maybe lucky...
if you can set up the new tank,if you can remove the decor and gravel from the 5 gallon and transfer it to the 20 gallon and fill it up half way or 3/4 with treated water,and let the filter and heater run until the water is about the same temperature that in the 5 gallon tank...then place the fish in a bucket with some water from the 5 gallon tank and the rest of the water transfer it to the 20 gallon tank and if you can transfer the 5 gallon filter to the 20 gallon as well and let it run together with the new filter for at least 2 weeks...when introducing the fish and shrimp to the new tank you need to acclimate them like if they were new fish...hope this helps.


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[ImACoolguy]

Skip the old tank water... There's very, very little bacteria in it. Not enough to even make a noticeable difference. You would just be adding nitrates to the tank.

I would use your old filter from the 5g and run it on the new tank. Because the old filter is cycled this will hold your cycle till you can get the new filter to cycle(takes around a month). Test every day for a little bit after setup to ensure there is no spikes in parameters.

IMO I wouldn't reuse the old substrate either. Like water, it doesn't hold much bacteria and can Barbour nitrates. If you really want to use it again, clean it first.

Hope this helps


Caleb