Algae in Filter/Pump Hoses

A couple of months ago I re-plumbed my 55 gallon freshwater aquarium.
I added 6 feet of hose to neatly place the filter/pump inlet at the
opposite end of tank from the outlet. I now notice a great deal of
algae growth covering the inside surface of the new hose. I did not
change the original outlet hose which has been in use for about 3
years and has no algae deposits on the inside. Also, there are no
algae deposits on the short section of the original inlet hose that I
did not change between the pump and quick-disconnect fitting.

When I purchased the new hose, I was told that it was OEM for the
Eheim pump that I use, although it is a different color and has no
markings like the original.

Question: Is this algae build-up due to material composition
differences between the two hoses or is it possibly due to some food
source that was in the new hose? If it is the latter, can I clean the
hoses and expect the hoses to remain algae free? If not, then I guess
I need to get authentic Eheim replacement hoses that appear to be
algae-resistant.