T5 depth penetration?

How deep to T5 bulbs penetrate effeciently into the aquarium.

 

I have heard that generally T5s will penetrate to about 15 inches and still be enough useful light for photosynthesis. I would try to reach 5 watts per gallon.

 

I have heard 20 inches at the most. You really need to consider where you put every coral on your LR.

 

I believe it depends what you want to keep at what depth. If you want to keep acropora you may not want to keep them 30" deep, if you're just keeping some softies then 30" might be OK. I believe T5s (with good bulbs/ballasts/reflectors, subpar components reduce this greatly) can keep a lot of acros/high light species up to maybe 10-15" down quite well from what I understand, maybe even a little deeper depending entirely on the organism.

 

No difference between MH and T5 upto 18 inches and then it starts to wane. I wouldn't use T5s in a tank that is more than 24 inches deep. However, it depends on the type of bulb you use also. Use a good bulb with a good fixture and you can pretty much do anything in a tank upto 24" in depth. I have a 90g that is going to get it's 8x54W TEK with UVLs by end of month. I plan on starting SPS and clams later in the year.