Setting up quick 20g tank to fishsit 2 clowns, 1 goby and shrimp till early next year. Must be ready for fish on Thanksgiving. Using water, rock, some seed sand and media from my IM SR-80 tank. I have extra everything to use but powerhead pumps. Not wanting to put a lot of money into it, what size Jabeo wavemaker pumps should I use, and do I really need 2? Thanks in advance.