How much light per square metre...

[mully1982]

... is sufficient? I have a 3 metre by 2 metre grow space and 60 plants. Can anyone give me an idea of how many 600 watt HPS lights I'll need in the flowering phase?

Thanks in advance

 

[Sunshine Closet]

The sun is 10000 lumens per sq. ft. You have roughly 18 sq ft, so you'd need 180000 lumens. I don't use HPS, but IIRC a 600w HPS is about 90000 lumens. So two lights should cover you.

 

[mully1982]

The sun is 10000 lumens per sq. ft. You have roughly 18 sq ft, so you'd need 180000 lumens. I don't use HPS, but IIRC a 600w HPS is about 90000 lumens. So two lights should cover you.

Cheers Sunshine... Some dude was telling me I needed 5. The same dude who owns our local hydro store funnily enough... He's been rumbled

 

[Sunshine Closet]

Wait, you have 9 feet x 6 feet. For some reason I forgot to convert the 2 meters to feet, which would be six feet roughly. That means 9 feet multiplied by 6 feet (not 2 feet). That's 54 square feet (not eighteen. My calculations were way off.

Either way you want 10000 per square foot for maximum yeild. My calculations are saying 6 lights? I guess he was right.

Sorry.... I blame wake and bake.

 

[frmrboi]

Either way you want 10000 per square foot for maximum yeild. My calculations are saying 6 lights? I guess he was right..

I agree, 5 might work OK but it's not ideal.

 

[mully1982]

Wait, you have 9 feet x 6 feet. For some reason I forgot to convert the 2 meters to feet, which would be six feet roughly. That means 9 feet multiplied by 6 feet (not 2 feet). That's 54 square feet (not eighteen. My calculations were way off.

Either way you want 10000 per square foot for maximum yeild. My calculations are saying 6 lights? I guess he was right.

Sorry.... I blame wake and bake.

That's bad times indeed...

 

[fred flintstoned]

A 600W will cover 3'x3' rather well. You have 6.6'x10'. So, yep, 6 lights.
Fred