Ok...so this IS my first tank, and I know that the odds are against me, but i WILL make this tank survive. So, today I started a one week "wet test" to check for leaks... Im not sure that there will be enough water movement with the small filter that i have...I'm on a tight budget, so i want to do this right, but also for the lowest price...so do you think i will need a power head? Or will placeing most of the coral under the waterfall be enough current? This is my 10 gallon tank so far: