Originally Posted by ericwithac
I would say 4-6. Generally 4-5 GPW is a good guesstimate, although im not as familiar with SW
as I am with FW
Do you mean WPG
? When it comes down to it, WPG
is a poor measure of light in any tank. There's a ton of factors that come into play in a tank such as height or the tank and distance above the water the fixture is.
Originally Posted by mr_X
Well, judging by the PAR38 lamps on ebay, They seem to have anywhere from 3 to 18 LEDs per unit. I would say to shoot for somewhere in the middle. If you are using Cree LEDs consider that they will have somewhat higher output also.
Also, the spread- I'm assuming you will be using 120 degree optics?
Are you sticking with just blues and whites, or will you add some violets as well?
In the end, if the fixture is dimmable, too many LEDs is no problem...not enough is a big problem!
I believe the driver I have can handle 10 LEDs so I might go with that. The aquarium is made that I can easily add more LEDs down the road if I need to.
I'm planning on a duncan and maybe some encrusting and branching montiporas along with some zoas / palys for my corals in there at the moment.
I was planning on just whites and blues. I was thinking 6 blues and 4 whites. The white bulbs give 5300k to 8300k so I figured that more blue would be beneficial.
Taking a look back at them, the white LEDs I have are 5w each. I will be going with the 120 degree optics.