Gillie
Aquarium Advice Addict
How do I calculate the proper wpg for a 20 gal long? I plan on using a pc bulb.
Lighting question
- Thread starter Gillie
- Start date
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This all depends on what you mean by 'proper wpg'. In its purest sense you would just take the total number of watts over the aquarium divided by the number of gallons (20). If you are wanting to try to figure out how that number relates to the 'wpg rule', then you would need to use an appropriate conversion from PC to T12. If you don't have the necessary information on the bulb to be able to compare efficiency, then 1.41 is a reasonable multiplier based on a sampling of PC bulbs.
A 20 gallon long is large enough that those calculations will give you a descent estimate of the amount of light over your aquarium. There are multiple other factors that come into play, like the quality of the reflector, distance of the bulbs from the surface of the water, and whether or not you're using a glass canopy. These and many other factors will play a large part in the functional light level in your aquarium.
A 20 gallon long is large enough that those calculations will give you a descent estimate of the amount of light over your aquarium. There are multiple other factors that come into play, like the quality of the reflector, distance of the bulbs from the surface of the water, and whether or not you're using a glass canopy. These and many other factors will play a large part in the functional light level in your aquarium.
travis simonson
Aquarium Advice Addict
WPG is just a rough estimation of your light intensity. A 20G long is a bit shallower than a standard 20G high so the light will be more intense as compared to such. Here's a link to an Excel spreadsheet developed by one of our members that will give you a more accurate estimation of your relative WPG. There is also a sticky at the top of this forum regarding updating the WPG rule.
Hope this helps
Hope this helps
travis simonson
Aquarium Advice Addict
Dang, Purrbox beat me to it again
OP
OP
Gillie
Aquarium Advice Addict
Sorry I was thinking high light, I wasn't sure if the lack of height in the tank made a big difference or not.as for the reflector I will probably be using polished aluminum, and nothing other than a glass top. Thanks for the help.
