Trickle filters do have a problem - if there's a power cut, the water stops flowing through them and the media can dry out killing the bacteria.
As Skull says, the best option is an external filter. But rather than run a new filter alongside the old one, a better way is to put all the media from the old filter into the new one and fill up the gaps with the media that comes with the new one. If you don't want to keep the old media long term, wait a couple of months thn replace the old media a bit at a time with a month between bits till all the old has been replaced with the new filter's proper media.
This way is better because if yuo run both filters together, the bacteria will spread out into both filters, the proportion in each filter depending on the amount of media in each one. Then when you remove the old one, you'll lose all the bacteria in that one. You also need to run both for at least six weeks. Putting some old media into the new filter would speed up the colonisation of the new one.
If you don't want to get an external, have a look at Ehiem Biopowers. The 240 would be the size for your tank. I have that one in my 125 litre (it is actually rated for up to 240 litres) and have had no problems with it. It is also very easy to use with media designed for a different filter making it easy to swap filters as described above.