is one watt equal to another watt ?

[Rxfisher]

I've been hanging around reading a lot, 90 gallon 4 foot x 24 inch FW has been up and running for 13 years. Had a great time with South American Cichlids, now that the last has passed on, wanted to go to angels with lightly planted low tech plants.

Now have 2X 48 inch 32 watt 6500K bulbs for light.

Looked all over to get the best light, decided on catalina 3 X 54 watts two circuits. Just got it, now learning, Best light, but may instantly put me into high tech mode. So I was running about 1000 watts a day, 64 watts X 15 hours. Plants slowly melted after about a month, or just are hanging on.

If I run 1 32 watt with just one of the 3 54 watts will that give me enough light and keep me without algae blooms. If I need more light could I just add a couple hours in afternoon of other 2 54 to give a pulse...or will that fry everything.

[jetajockey]

I get how you are calculating wattage by time but I don't think it really serves much of a purpose.

Light intensity is not the same for different fixtures and fixture types, so WPG is very inaccurate.

I would nix the T8's (32w) completely and just run the 3x54w, it's plenty. The catalina fixtures are great and you may find yourself gong down to 2 bulbs at some point if you don't intend on running co2.

Have a look at this chart, it was made using similar quality fixtures to the catalina one that you have.
PAR vs Distance, T5, T12, PC - New Chart

[Link119]

Plus, 15 hours a day is too much. Stick to 8-12 hours a day...

[Rxfisher]

If I got the chart right, 2 bulb would be top of medium range and 3 would be high in co2 range, if light on top of tank which I want

[jetajockey]

yes, also factor in substrate height. It's just a guideline but a good start.

[malfist]

I have a background in electrical engineering so trust me when I say this: Wattage of the light bulb is an extremely poor measurement of light intensity.

If you don't believe me, go to walmart and pull out all the 60 Watt bulbs and compare the luminosity, you'll notice there's a considerable difference.

Lumen's is probably the best measurement for you that you're going to get. Lumiens are a measurement of how much light is emitted by the device. The best measurement, and you're rarely going to get this on anything but LED's is candela. Candela measures light how much light reaches a target at a specific angle.

[Rxfisher]

I appreciate the info from u and all the form, so after u get all the general rules it's back to observation and experimentation.
I'll start with 2x54 for 6 hrs and increase 1/2 hr a week till first sign of algea.