My heater guard DIY idea, This is to stop "heater burn" not to protect from big angry oscars 
1, Grab yourself some flexable piping, Costs pennys! Normally used for ponds etc i believe.. I brought to use as a hiding spot for Spiny eels
http://imageshack.us/photo/my-images/35/dx6q.jpg/
http://imageshack.us/photo/my-images/844/evsi.jpg/
2, Check this pipe fit over your heater.. The better fit the better the finished product will look
http://imageshack.us/photo/my-images/571/yuj7.jpg/
3, Take a pair of scissors and cut your way along the ridge of the flexable piping
http://imageshack.us/photo/my-images/31/h9hc.jpg/
4, You will come out with something along the lines of this
http://imageshack.us/photo/my-images/14/69jm.jpg/
5, Go ahead and put it on/over your aquariums heater and use cable ties to fix into place (top and bottom)
http://imageshack.us/photo/my-images/189/pbcj.jpg/
http://imageshack.us/photo/my-images/96/ni26.jpg/
6, Trim down the access cable tie plastic, Trim down accsess flexable piping and place back in aquarium and get yourself a cup of tea
http://imageshack.us/photo/my-images/32/fnz9.jpg/
Hope this is helpful to someone, Please let me know what you think (
Thanks for reading! Sorry for all links to pictures. I'm useless with computers!

1, Grab yourself some flexable piping, Costs pennys! Normally used for ponds etc i believe.. I brought to use as a hiding spot for Spiny eels

http://imageshack.us/photo/my-images/35/dx6q.jpg/
http://imageshack.us/photo/my-images/844/evsi.jpg/
2, Check this pipe fit over your heater.. The better fit the better the finished product will look
http://imageshack.us/photo/my-images/571/yuj7.jpg/
3, Take a pair of scissors and cut your way along the ridge of the flexable piping
http://imageshack.us/photo/my-images/31/h9hc.jpg/
4, You will come out with something along the lines of this
http://imageshack.us/photo/my-images/14/69jm.jpg/
5, Go ahead and put it on/over your aquariums heater and use cable ties to fix into place (top and bottom)
http://imageshack.us/photo/my-images/189/pbcj.jpg/
http://imageshack.us/photo/my-images/96/ni26.jpg/
6, Trim down the access cable tie plastic, Trim down accsess flexable piping and place back in aquarium and get yourself a cup of tea

http://imageshack.us/photo/my-images/32/fnz9.jpg/
Hope this is helpful to someone, Please let me know what you think (

Thanks for reading! Sorry for all links to pictures. I'm useless with computers!