[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Your suggestions for lighting please

Tim wrote:

> I'm conceptualizing a new 75g (48 x 18 x 20) planted tank and puzzling a bit
> I guess the rule of thumb usually tossed around for lighting is 2-4 watts
> per gallon. If I split the difference and aimed for 3 watts/gallon that
> would mean 225 watts. My first question is is that a reasonable figure?

Yes, I've got 240w over my 75g, and it's a pretty good amount of light.  It
could even stand to be a little higher, but I've got 6x40 tubes with just
a simple flat reflector behind them.  

> ballpark but I don't know if a single bulb will work well for a four foot
> long tank.

no, it wouldn't.   And most 75s I've seen have a brace in the center, right 
where the single MH would be...

> I'm intrigued by the idea of dimming because I can't imagine that it is all
> that good for fish (maybe plants, too) to have to instantaneously transition
> from darkness to full mid-day sun and vice versa. Is this of any practical

I don't think it really hurts, but if you get multiple lights, you can 
just turn them on at staggered times using timers.   In my case, of my 6
tubes, two come on first, then 20-30 minutes later, the other 4 come on.