I recently got a new 125 gallon, and am getting ready to fill it. I currently have 3 other tanks, that are fully cycled and running. If i put the used water, taken from the water changes on the other tanks, into the 125, would this help speed up the cycling process? I would be able to add right around 40 used gallons on the first initial fill up, then could use another 40 used gallons or so to top it off a week or two later.

I also have an Eheim 2217 canister, and an emperor 400 set up on seperate tanks, so that they will already have bacteria built up on the bio-media when i move them to the new tank. If it helps, i can also take some rock from one of my larger tanks, to add to the new one to help speed up the cycling process at all.

The reason id like to speed up the process, is because i really need to get my oscars to the big tank, before they do outgrow their current tanks, and i know it can usually take around 4-6 weeks to cycle if using all new equipment and water, and i was hoping to be able to speed it up a few weeks.

Thanks in advance, for any help on this!

cashmoney6980 wrote:


Whatever you can add helps. So go for it.

I used the feeder method to speed up my cycling. I also would put water from the other tank into the cycling tank when I did changes - back then it was 2x a week I was doing changes. And I took my filter media (some of it) and put it in my sump.

It moved mine along nicely and had a cycled tank in 2 1/2 weeks. (120 gallon)

Good luck and happy cycling!

my question is "do the big tank location will be different from the
smaller tank location?"... if it does, then you can move everything:
water, decor, and fish.... add new water (pre-treated with conditioner)
run the existing filter in it together with a new one and bingo! you
have fully cycled huge tank!

Fill you new tank with as much water as you can from the others. The best thing you can do to cycle your filter instantly is to take some media from your other filters and put them in your new filter AT THE SAME TIME as adding your new fish. Then test daily to make sure you dont get any ammonia or nitrite. If you do get a reading for this then daily water changes of 25% until it is cycled. When we talk about a cycled tank we really me a cycled filter

Check this out

www.oscarfishlover.com/how-to-cycle-a-tank