hi all I have the marina 60 aquarium 60L and I have the superfish aquaflow 200 I don't think its good enough it worked great in my 50 until my superfish 50l started leaking my question is if I buy a fluval u2 and put in the marina with the superfish will the cycle start again with a old filter already in the tank and a new one thanks darryl

If the first filter is working and the tank is fully cycled then adding another filter and running them together will not disrupt the cycle. If you plan to remove the 2nd filter then it should be left a good couple of months to let the new filter get a full bacteria colony. My advice would be to keep both filters, firstly you can never get enough filtration, secondly its a great backup if one ever breaks.

ok thanks yer I don't want to filters in the tank permanently so if I put the new one in with the old one for a month or to and take the old one out it should be fine

Alternately, you can move the filter media from the old filter into the new filter (assuming it fits), for an instantly cycled new filter.

Move the media as this.foolish.heart suggests. Running two filters side-by-side when one is mature and has enough bacteria for the tank's bioload is not a safe way to proceed. The bacterial colonies only ever grow to a size sufficient to cope with the bioload of the tank. They also stick very firmly to the media and don't go travelling in the water so at whatever point you remove the old filter you will be at risk of a spike in ammonia/nitrite or even having to do a full fish-in cycle. If you move the media into the new filter you also move the bacteria so have an instant cycle on the new filter. If it won't fit, cut it up.

it wont fit as the superfish on I have not is a sponge with carbon media in it and the u2 I was going to get has the sponge with the carbon pads in

Don't worry about the carbon pads, they're only useful to remove meds or other impurities. If you leave them in too long they stop working and just provide surface area for the bacteria to grow on. Take the media out, chop it up and squdge it in. You should be fine.