Until there is enough beneficial bacteria to process the waste produced by the fish you intend to keep in it. If it's only going to be a home to one betta, it won't take much at all. Move a bit of media from another tank and it will be ready to go.
CT - As we have been chatting about you buying some of my fish - you can always take with you some "squeeze" from my filters - this will kick start the nitrifying process but once started you will need to keep the bacteria "fed" in order that it can multiply to support a bio-load of fish. If however you intend to place just one Beta in the tank a "squeeze" should be sufficient to colonise the filter media to support the one fish from pretty much 24 hours after startoff (allowing the murk to settle).
If however you are going to add more fish you should do this slowly - the beta wont make much waste and the colonies of bacteria will be small therefore adding more fish will increase the bio-load and thus the bacteria wont be able to cope with the increased waste matter from the additional fish - adding no more than 3 small fish per week is a sensible approach, this way the bacteria will build up slowly to cope with the extra waste matter but the toxins wont rise to a level where the fish are at risk (Ammonia and Nitrite).
All said and done, I would ALWAYS recommend the fishless cycle using Ammonia to 50ppm.
Well, I'm on 7 and a half weeks and not even getting 0 in 12 hours yet, and that was with changing half the media for mature stuff from LFS and filter rinsings.
Not to be discouraging, but to let you know it can take a long time. If you're anything like me, I like to know what I'm letting myself in for when I start
Well I have a LFS that would give me the filter stuff and I have 2 mature tanks in my house so getting other Filter media isnt a problem. The last thing I would like to do is think its ready and lose a good fish for something stupid
mate as you have two tank's,go for a filter clean on both tank's squeezing all the muck into a bucket<container>then soak the new media in the bucket for a while,if you have filter's where you have more than one media in use half of the media on the new filter,depending on what filters you have?
then this should help set up very quick, if using media from exsiting filters you can get on with it striaght away
One is a fuval 105 exturnal while the other tank is a fuval 4 plus i think. I would be able to change filter pads as it wouldnt be same size... So Will just have to do what Nelly said and put it in bucket and soak new filter pads in that. So after doing that for a couple of day... Could they fishy go in
Well good luck with it. I might just do it the old fashon way I done my 2.5 ft tank...
Put everything I want in there (Plants objects etc) water and then add a little bit of media from my tank and some fish food every day to keep it dirty and living,,, And do a test in about a months time etc.