I will try not to wander 
I have a 30 gallon tall that I want to put new lights on. Every tank that I have had has had some kind of flourscent lighting.
I am debating on putting MH on this one. It is in the basement so heat is not a problem. I will probably go with a 150 or 175 retro or pendant for the tank. I could go 250, but that seems like overkill.
My question (no 1 at least) What is the difference between HQI and single ended? (besides one having one end and one having two
Is there an advantage of one over the other.
I could also go t5's but I thought I might try something different.
ciao
johnny

I have a 30 gallon tall that I want to put new lights on. Every tank that I have had has had some kind of flourscent lighting.
I am debating on putting MH on this one. It is in the basement so heat is not a problem. I will probably go with a 150 or 175 retro or pendant for the tank. I could go 250, but that seems like overkill.
My question (no 1 at least) What is the difference between HQI and single ended? (besides one having one end and one having two

I could also go t5's but I thought I might try something different.
ciao
johnny