Difference between HQI, EYE, standard, and electric ballasts

[Aquattro]

Josh, there is no single answer for that. Depending on the bulb you're using and which ballast, the answer is different. The "standard" ballasts are just that..tar ballasts. EYE are Mercury Vapor ballasts to run Iwasaki bulbs. Some HQI are High Pressure Sodium, some are not. Different e-ballasts act differently on different bulbs.
The best question to ask is specific to the bulb/wattage you want to run. Then you can narow things down a bit!!