How close to the water can the light sit without a lid?

[mike31154]

Can you provide additional details on the lights? I assume they are T5 but could be another type of fluorescent? I'm also curious about the "ballast that holds..." the lights. Or are you talking about the fixture? Is it a retro fit type set up? In any case, as mentioned, once you remove the glass cover from the tank, which is a good idea for other reasons than the lighting, you will want to raise them up a little higher to protect the lamps and reflectors, if fitted. I ended up hanging my T5HO retrofit set up from the ceiling to get the desired clearance. Easier to access the tank as opposed to working around light fixture legs.