Merging 2 20Gs into a 55G

[MDBuckeye]

I have 2 established planted 20G High tanks community tanks, and I am thinking combining both in a new 55G.  The larger aquarium would give the fish more room to swim, and I would only have to maintain one aquarium instead of two. Both aquariums are stocked with similar peaceful community fish. I plan on transferring the substrate, plants, and décor from the 20 gallons into the 55. This would at least transfer beneficial bacteria from the cycled tanks to the new sterile one. Would anyone have any advise on how to do this safely without harming the fish, or point me to the direction of some websites or YouTube videos? Particularly, is it safer to transfer one, let the 55 cycle, and then transfer the second, or could I do both safely at the sometime. 

[Drew Schmidt]

If it were me these are the steps I would take.

1. give the new 55 a good rinse making sure to get rid of all the dust and residue from being at the store.

2. If you want a background on the new tank get it put on then get the 55 where you want it placed. If you want the 55 where the 2 tanks currently are you may need to change up some of these instructions.

3. Pull out all plants and decor from 1 of the 20 gallons and let them float in the other 20 gallon 

4. Start remove water from the 20 gallon saving some of it in a clean 5 gallon bucket. If running a sponge filter you could also place it in the bucket to keep it from drying out.

5. Remove the fish when they start having limited space to run and place them in the bucket. 
 

6. Once all fish are removed from the first tank continue draining till you can’t get any more water out.

7. Remove and transfer the substrate. I usually use a clean dust pan to remove substrate using it like a scoop. 
 

8. Pull out all the plants in the second tank including the ones you had floating. Place the plants in the bucket.

9. Lower the water in the second tank and start removing the fish and placing them in the bucket that now has all the plants and fish from the first tank.

10. Remove substrate from the second tank and place it in the 55. Spread it out to how you want it and see if you need to add any more new substrate. 
 

11. Fill the new tank slowly and add dechlorinator. Depending on how clear the water is when refilling I may add the fish at this point or if it is really murky I would wait till I could see through the tank front to back.

12. Transfer both filters and the plants into the 55.

13. Have fun aquascaping. 
 

You may go through a small cycle but by using everything from the old tanks you may not even notice it with the plants. 
 

That is what I would do and I hope that helps you.

 

[MDBuckeye]

These steps help a lot. Thank you so much!

[Brackon]

On 7/8/2021 at 7:13 AM, Drew Schmidt said:

If it were me these are the steps I would take.

1. give the new 55 a good rinse making sure to get rid of all the dust and residue from being at the store.

2. If you want a background on the new tank get it put on then get the 55 where you want it placed. If you want the 55 where the 2 tanks currently are you may need to change up some of these instructions.

3. Pull out all plants and decor from 1 of the 20 gallons and let them float in the other 20 gallon 

4. Start remove water from the 20 gallon saving some of it in a clean 5 gallon bucket. If running a sponge filter you could also place it in the bucket to keep it from drying out.

5. Remove the fish when they start having limited space to run and place them in the bucket. 
 

6. Once all fish are removed from the first tank continue draining till you can’t get any more water out.

7. Remove and transfer the substrate. I usually use a clean dust pan to remove substrate using it like a scoop. 
 

8. Pull out all the plants in the second tank including the ones you had floating. Place the plants in the bucket.

9. Lower the water in the second tank and start removing the fish and placing them in the bucket that now has all the plants and fish from the first tank.

10. Remove substrate from the second tank and place it in the 55. Spread it out to how you want it and see if you need to add any more new substrate. 
 

11. Fill the new tank slowly and add dechlorinator. Depending on how clear the water is when refilling I may add the fish at this point or if it is really murky I would wait till I could see through the tank front to back.

12. Transfer both filters and the plants into the 55.

13. Have fun aquascaping. 
 

You may go through a small cycle but by using everything from the old tanks you may not even notice it with the plants. 
 

That is what I would do and I hope that helps you.

 

This is how I move my tanks or size up my tanks and it typically works but personally I always keep an eye on it and do a few small water changes over the first 2 weeks

[Odd Duck]

I would strongly suggest removing some water first and saving this clean water in the fish buckets.

THEN start pulling out plants and decor since moving plants, etc, will stir up the substrate and cloud the water.

Then follow all the other, very well laid out instructions.