Just Dump The Whole Tank In?

[Matt Winter]

Hi - I just got a 55 gallon tank. I don't want this to be an upgrade so much as an addition, as I'm happy with what's in my 20 gal long already. I have an idea for skipping cycling I wanted to run by someone -I wanted to just dump (but gently) the entire contents of my old tank, and it's filter, into my new one - run extra filters and slowly add water until it's full. Then in a few weeks the new tank and filters would have a decent bacterial community and I could just move my fish back into their old tank along with their old filter, and start adding new fish to the new tank. Would this work?

Any input would be much appreciated.

 

[rdd1952]

Dumping the water from the cycled tank into the new one won't help. There isn't any bacteria in the water, only on the filter/media with a minute amount on the plants/decor and in he substrate. The best thing to do is to take media from your existing filter and add it to the new filter. Go through a fishless cycle like that. it shouldn't take long since you are seeding with media that already contains bacteria.

If you ran both your old and new filter on the new tank, the new filter still wouldn't have enough bacteria to support many fish. There is only enough bacteria in the tank to support the current fish load. So even if you ran the 2 filter together for a month. There wouldn't be any more bacteria in the tank at the end of the month than when you started. It would just be spread between the 2 filters with the one having the most flow containing the most bacteria since it is bringing more food to them.

Seeding is definitely the easiest way and probably will have both tanks running at the same time quicker than the way you are talking about.

 

[MeanHoney]

I'm in the process of doing something very similar. I just bought a 75 gallon. Based on the advice I received from others on this board. I moved the filter (running with the new filter for the 75) and fish from my 20 L to the new tank. It's 10 days after the move and ammonia and nitrate have stayed at 0 and nitrate is 5 ppm (my tap water is 0). So things are working well. In another 1 to 2 weeks, I will move the filter back to the old tank and begin using it as a a quarantine tank to stock the 75. So... I think your idea will work, but as rd said, you don't need to move the water or the substrate - just the filter.

 

[BigIan]

it would work, but its not the best way....
you culd run the new filter in tandem on your old tank for a few weeks to seed it, then slowly stock your new tank. (i`ve done this before and it works fine)
you could also use some media from your old tank to seed the new one and also wash the old filter and wash the new media out in the old mucky water to seed it

(or a combination of all of the above

 

[rdd1952]

MeanHoney, keep in mind that your new 75 gallon tank will only be cycled for the few fish that you had in the 20L. You will still have to add fish slowly to keep from seeing an ammonia spike. Doubling the load each time is about all you want to do. That way the bacteria colony will only have to double itself to catch up. That should happen in a day.

 

[MeanHoney]

MeanHoney, keep in mind that your new 75 gallon tank will only be cycled for the few fish that you had in the 20L. You will still have to add fish slowly to keep from seeing an ammonia spike. Doubling the load each time is about all you want to do. That way the bacteria colony will only have to double itself to catch up. That should happen in a day.

Thanks for advice. That was my plan, especially since I'm using the 20 as a quarantine tank.