Ways to protect my ray from burning itself on the heater!?!?!??

use a pvc pipe as a heater guard and drill some holes in it for water to pass through. There is also heater guards you can purchase made for this purpose.

Do u have a sump? If u do I woud buy a titanium heater and put it in there...And I know this is off topic but I would look into a bigger tank if ur keeping rays in a 90 gallon...

Are you using a sump??? If u are I would buy a titanium heater and put ur heater in ur sump....And I know this is off topic but I would recommend u to look into buying a bigger tank if ur housing rays...

jus buy the fluval E digital heater. it comes w. protection

PVC pipe with holes is the quickest and easiest fix.
There's a plastic mesh called Naltex you can buy and form your own barrier with as well.

I use this mesh tubing. Its availible from Aquatic Eco Systems

I use heaters that come with a guard in all of my ray tanks. They work great and include a controller.

http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=22277

They also sell just the shield if you have a heater that will fit in it, never tried that route myself.

http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=22276

You could also use an inline heater on one of your pumps, or as others have suggested a PVC pipe with holes or the mesh would work to.

A note on the fluval e series heaters mentioned above, they are not fully submersible heaters, I was researching them last night before ordering another one of the ones above. You have to keep the top part of them above the water, if that's not a problem for you they would work to.

The easyest way is deffinetly to stack wood infront of it, it has to be so packed that the ray dont come inn there. Shouldnt be hard, since rays are pretty big fromt hey are born.

Besides the PVC pipe the guys told you about already (which works good and is the cheapest way)
You can either buy the Fluval E serious heaters or the Rena Smart Heaters. Both are build to make sure they will not burn your stock.

If you are running a sump with your system, then just place the heater in your sump.