new tank

[gary007]

new tank 20g been set up and had heater and filter running for 2days now. if i was to put an old filter in there and old water that has the goodness in it, would that speed up the cycle? ammonia is at 1 from the test. i want to move fish from 7g tank to this 20g u see and would put some of their water in and the bonus filter with good bacteria there. should be safe?

[discuspaul]

There is no nitrifying bacteria in the water column, so adding old water from your other tank will not help. Your established filter moved over from your 7 gal. should have sufficient BB for you to transfer your existing fish to the new tank.
But if you're planning on adding more fish to that tank, do it gradually, just 1 or 2 fish at a time, to allow your seeding to catch up to the larger bio-load. Give it a few days before adding more fish again, and check your params (ammonia/nitrites, nitrates) every couple of days to ensure/confirm that your BB colony is progressing ok.

[gary007]

i have 2 corydora catfish, i think they are hardiest and theres another 11 small fish to put in, they are barbs and very active in large groups but may not survive right now in new 20g.

[discuspaul]

Where are the other 11 small fish (the barbs) ?
At a friend's ? At a LFS ? Can you pick them up in batches ?
Transfer your seeded filter to the new 20 gal, along with the 2 Corydoras, and just add the barbs 2 or 3 at a time, - 2-3 days apart.

[Diztrbd1]

I believe they are in their 7gal tank if I am reading correctly

[gary007]

yes in 7g at the moment, just for now. so the filter in 20g could not handle all the fish waste right now on day 3? u see this filter has 2 sponges and a box with little balls that move around. they say it breaks down whats harmful to the fish making it safe for fish to go in. its a filter by tetra.

[gary007]

its a mixture of green, orange, and albino tiger barbs, theres 11 in total oh and 2 catfish that are my cleaning crew lol cant have a pleco in here tank length is 2foot and 15inches high.

[discuspaul]

I see. The 2 Cories and the 11 Barbs are now in the 7 gal. & are doing OK ?
Then you should be ok with transferring the old filter intact from your 7 gal. and all the fish at once, at the same time. If the bio-filtration in your 7 was handling the load, it will do so as well in the 20 gal.
Run the 20 gal with both filters in it for 3 weeks or so, then it will be safe to remove the other smaller filter you had in the 7. But as I said before, if you're adding more fish to the 20, do it gradually, in stages - i.e. don't just add 8 or 10 more fish at once.