Drain pan drain

[plexman44]

I do maintenance on 65 unit retirement home with Magic-pak units 36EMC.... where drain pan for A/C is steel. They started rusting after first year and second year the drains would plug up in hose under pan. Water sometimes ran outside building and turned siding brown or it would flood closet space with water and mold would appear. Can I move loop in hose down to condenser apartment and make a bigger loop so it doesn't plug up. Is there a remedy for stopping rust in drain pans?

[Admin]

Check out the products below,

https://cleanac.com/products/resurface/

https://cleanac.com/products/panguard/

[plexman44]

Model number may be 36MGE4.... Allied brand.