[Myka]

Originally Posted by StirCrazy

actually, it is very accurate, I took my PAR meter down to Safari pets and did a direct comparison between PC/T5/MH the 250 watt MH still had almost twice the PAR at twice the distance, and yes it was high output T5. I will say though that the T5 impressed me enough for me to buy one and put it on my fresh water planted tank as it had 40% more output as the same size of PC.

What you do not know though is how old the bulbs were in comparison to eachother. Also the type/brand of ballast and reflectors play a huge role in PAR as well. Although your "general" comparison may be "somewhat" accurate.

Generally, I have found that the T5 Euro SPS tanks have a lower watt per gallon than the usual North American MH SPS tanks (on similarly dimensioned tanks). That is why I said that you generally need lower watts with T5s than you do with MH. Maybe "intensity" was a bad choice of words on my part...

If you do a search on "watt per gallon" you are going to see a lot of rants from me about it as it is a totally useless measurement and or comparison that in no way relates to anything except the exact same type of lighting at the exact same color temp on the exact same dimension tank.

I agree. I used the "watt per gallon" as a general comparison to similar SPS dominated tanks, and only in comparison of T5s to T5s or MH to MH. I am very aware that wpg is an inaccurate way of defining lighting intensity, BUT it is a good point to start from.

If you want to keep high light corals on the middle of your tank then yes T5's will be good, but if you want to keep some on the bottom of your tank, you will be better off with MH.

Ok...I see where we're not seeing eye to eye here. Thanks for taking the time to write out your explanation even though I am in the understanding of this.

I do know that T5s (and every other form of lighting) are limited to the depth they will light. Many other factors; like water clarity, reflectors, ballasts, etc also play a part. I have no interest in keeping SPS at the bottom of my tank. I chose to have a 24" tall and only 18" wide tank because of the look I would like to achieve.

Essentially, I would like to try to (simply) replicate a wild reef shelf (I think it would be called). With high light SPS on the top, lower light SPS lower, higher light LPS in the middle, lower light LPS lower down, and the lowest light corals down low. The way I will be building my rocks will make for a plateau type layout up high on the left, as well as a bench with sand in it for a clam. Under the plateau on the left side will be a low lit area for low light corals. The rocks then taper off on the right side of the tank creating a tiered effect.

So, in my case I do not need the light to have high intensity low down. I would like to be able to keep the lower light LPS corals near the bottom though. I will have a 3" sandbed as well.

What do you think of the T5 idea for this type of tank? I have decided that I want to go with the Sunlight Supply T5 Retro Fit kits instead of the Tek fixture. This way I can spread the lights out from front to back better. Good idea?