On a 45g bowfront I think you might be exceeding what one MP 20 can do. The wave dynamics in a bowfront are a bit trickier.
I know on a 34g square tank one MP 20 will work very well, as you can see in this link.
Click here to visit our site and see an MP 20 running on a 34g Solana
The nice side of an MP 20 on that size of a tank is that the one pump gives you 44 times turn over rate in the tank
