New Tank With Used Filter

[Salam]

I picked up a used 142 l tank yesterday which I won on ebay (for a bargain price!). It came with a filter which has been used until recently. The seller said it should only take three days to cycle, but it doesn't sound right to me. Or is it true? Will a used filter need less cycling time?
Once it is ready I am going to put my fish from my current smaller tank into it, the sooner I could do it the better as I am having some platy fry soon and I want the smaller tank to be the breeder tank. Any help / advice will be appreciated.

And another question:
The tank has been used for three years and there are some watermarks. How can I clean them? Are there any chemicals that would tackle them but be ok for the fish? Otherwise I just need to scrub with warm water as much as possible.

 

[robert clements]

a littel bit longer then that mate. it will make it a short cycle some one on here will let you kown how long mate

 

[CezzaXV]

It depends what they mean by cycle. Many pet shops would have you believe that a cycle is nothing more than leaving a tank to run for a few days, but it's much more complicated (though not difficult). Depending on how long the filter has been out of water there may or may not be some of the beneficial bacteria still inside the filter. If recommend you do some reading on fishless cycling, then buy yourself a bottle of ammonia, a liquid test kit and put it into action. A fishless cycle starting from scratch can take anywhere up to two months, though there's a chance you're not starting from scratch and it could be quite a lot less.

 

[Salam]

Thanks for the replies. I went to the local pet shop yesterday and they told me anything between 2-6 weeks which sounds reasonable to me. They said to come back in two weeks with some water and they will test it for me (I have a testing kit, but it only checks the main things) and then we go from there. Someone also told me to use half of my old filter and add it to the new one when transferring the fish, so the good bacteria will be moved with them. Does that sound alright? Sorry, still so new to fishkeeping

 

[Juggler75]

The rule of thumb is that you can replace a third of the media in an established filter as the good bacteria should replenish their levels before any damage is done to the fishes in the tank the filter is on, assuming it is not overstocked.
The benefit for you is that the media you move across to the new filter will 'seed' the filter and therefore massively reduce any cycling that needs to be done, or provide enough good bacteria to support a small amount of livestock from the get go.

If you post more details of the donor filter/original tank and livestock and new filter the people on the board can give you some more advice