If a pod-equipped plane climbs with increased throttle, it has too much upthrust. But with a pod, you need SOME upthrust. The thrustline is higher than either the center of gravity or the center of drag. So, th ethrust make it want to dive. Adding the >Right< amount of upthrust will balance the diving moment with a lifting moment (and engine downwash over the tailplane). When you get it right, it will not want to change trim. Also, with that much upthust, the right side of the prop will be getting a much bigger bite of air, so wedge in generous right thust also. 3 degrees up, 3 degrees right is a starting point.

THAT BEING SAID: JRF's suggestion to mount floats is the right idea. Quick, easy, light, and easy to pop the wheels back on for some dirt-flying. Converting it to a flying boat requires changing everything about a plane but the horizontal stabilizer. This is not the effective way to go float flying.