Question about adequate water movement in a 150 tall

I currently have 2 hydor koralia 1500 circulation pumps in my 150 tall, and I'm thinking there isn't enough movement in my tank. I'm getting cyano in several dead spots in my rock work, and no matter how i position the pumps it doesn't seem like enough flow. I have the opportunity to buy 3 WP40s for $150 but I don't know if those would create enough flow either. Thoughts? Suggestions? Any help will be greatly appreciated. Other than the cyano, my tank looks great.