Lighting for a large tank wpg?? (no co2)

[TankZen]

Need help lighting my 180G....no Co2...EI dosing.

Initially I was thinking 3 (96w CF) 34in however this would give uneven lighting because two fixtures would stretch the entire tank and one would be behind in the middle. 1.6WPG

I'm wondering if I have 4x (96W coralife CF) will this be too much WPG for a no co2 tank. 2.13WPG

I have 4 coralife 34in fixtures that came with the tank. Tank dimensions 72x25x25.

Please help... I know too much light too little co2 can cause big problems.....

 

[jhunt]

WPG rule doesn't really work. Because of the height of your tank, even four 96W PC bulbs will probably still leave you in the low to low-medium light range. Two-36" two bulb T5HO fixtures or 4- 1 bulb 36" T5 fixtures suspended 4-6" over the top of the tank.

 

[dutchy]

I'd just try with what you have now. Low light is exactly what you want with a non CO2 tank. If you get algae, the intensity is probably to high. Then reduce by raising the lights or by using less lights. No more than 8 hours duration.