It's a problem.

The bacteria that make up the biological filter in a
SW tank are completely different from their
FW counterparts. The FW TSS won't work for you, nor will seeding from a FW tank.
Are you planning on adding live rock to your tank? IMO it is the best and most natural form of biological filtration for a marine tank and should be added, but not everyone chooses to do so and you can still be successful without live rock.
I'd recommend returning your clownfish if you can. A cycling tank is very hard on fish. If you want to add live rock, now is the time to do so. Any die off on your live rock will help to cycle your tank for you. If you have minimal die off and your rock is cured, it may not take long at all. If you don't want to add live rock, you can cycle the tank without fish, with a raw shrimp from the grocery store.
One more thing- nothing good happens in this hobby quickly. I'd recommend resisting the urge to use TSS or similar products to cycle your tank. TSS can be fine for FW tanks, but a marine tank is a whole different ballgame IMO. There is so much more patience involved with marine tanks... even a cycled marine tank can be easily overwhelmed by new additions if they are rushed. Marine tanks take much longer to become mature and stable than FW tanks.