How do things pay for themselves in the aquarium industry?

[Noob]

Ya I replaced all the thermostats, tinted some windows that get the most sun, replaced ddoors and storm doors.. My garage door and attic or next on my list.... Then it's the front windows that let out alot of energy.

Another thing you should look into is proper ventilation.
If your house has turbine vents, there is alot of hot air that is trapped in your attic.
Ridge vent with the proper amount of intake vents would be the best solution.

The radiant barrier is about $1.00 per sq foot, if i remember correctly.