Noticed I keep seeing bits of stuff in my radiator. Thinking I need to flush and clean the cooling system. Can someone recomend a flush/cleaner thats safe to use with a aluminum radiator?

I like to flush with the garden hose method. Pull the T stat and re-install the water neck. Rig up a garden hose adaptor for the top radiator hose. 1 1/2" or 1 1/4" pipe (iron or PVC works) adapted down to a garden hose with hardware store stuff works well. Then let it flow. You can also (carefully) rig up an air hose. Flush with water, empty it with air and repeat.

After doing this, you could use a cleaner but I kinda avoid them. They can attack some parts like seals. If you use a cleaner, flush afterwards with the garden hose.