Review the steps and equivalent output guide at this link....

http://keystoneballast.com/conversion

The truth about fluorescent lamps is as follows:

All fluorescent lamps require a tiny amount of mercury to produce the UV light that is converted to visible light by the powder coating. There is no phosphorus in a fluorescent lamp. The amount of mercury is a sphere with about the same diameter as the period at the end of this sentence. Any more is baggage.

All lamps of the same diameter are basically the same except for the buffer gas (argon, krypton, or neon) and the coil or electrode interface to the gas.

Each diameter is designed to run at a particular current that is usually optimum for that gas/pressure range of buffer gas. The gas type and pressure determines the voltage drop from one end of the lamp to the other, once it ignites. The ballast is usually designed to work as a current limiter with a fairly wide tolerance of lamp voltages. A family of products will tend to use the same current which makes them quite interchangeable.

The impedance of a lamp changes from megaohms (when off) to a few hundred ohms when on. Without the ballast, the current would increase until the wires sealed in the glass (at the ends of the lamp) becomes hot enough to crack the glass. Other things can also happen such as vaporizing of the wires which then redeposit inside with a nice mirror finish, given enough time before the air rushes in.

Typical fluorescent lamps are at low pressure to aid current flow. Higher pressure (Too many atoms) will interfere with propagation of electrons.

Mixing ballast types with lamp types is generally unsuccessful as it over drives or under drives the lamp. Lamps intended to operate at High Output or Very High Output have heaver coils (electrodes) to resist vaporization at the higher current. A High output lamp operates at roughly twice the normal lamp current. A VHO or very high output lamp operates at roughly four times the normal lamp current.

The light output peaks when the bulb temperature is maintained at about 40°C. Higher or lower temperatures reduce the light output. Energy saver lamps generally never reach this temperature because the Krypton fill gas tends to interfere a bit more with electron propagation. The lamp pressure of a Krypton filled bulb will therefore be slightly lower than other lamps in its family.

Lamp wattage is a function of arc length and current. The best return on investment in fluorescent lamps over the life expectancy is T8. Everything else is subject to a variety of failures to wide to mention.

Lastly, there are only two basic ways to operate a fluorescent lamp. One way provides energy to the coil (hot cathode) and the other way treats the coil as a simple electrode (cold cathode). All ballast types are some form of one or the other types. The ballast type that gets the most life from a lamp actually switches from hot cathode (to start the lamp) to cold cathode (to run the lamp). These ballasts will generally obtain more life from the product than it should provide.

Lamp life is determined by the rate of deterioration of the electrode and its coating.