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

[sphelps]

If you don't have any kind of shield between your bulbs and water you'll have to make sure you're using quality waterproof endcaps. Even then you'll want at least 3-4 inches otherwise the bulbs will likely burn out prematurely from the water splashing and salt build up.

[banditpowdercoat]

I hang my TEK light 3-4" above the water. But the reflectors get salted up, have to clean them every couple weeks

[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.

[jassz]

Rather than tell you something incorrect, I thought it would be best if I posted a thousand words with a picture or two. How do you tell if the endcaps are waterproof? Sorry, I bought this whole set up used, and it's my first tank so I don't know a lot of this stuff. Hanging it from the ceiling is a possibility in this spot, but I was worried it would swing too much, plus it's more difficult to remove to change bulbs etc.

[sphelps]

They don't have water proof caps so unless you want to risk creating a short circuit (leads to ballast/bulb failure or fires) you need some kind of shield to keep water out.

[fkshiu]

Originally Posted by jassz

Rather than tell you something incorrect, I thought it would be best if I posted a thousand words with a picture or two. How do you tell if the endcaps are waterproof? Sorry, I bought this whole set up used, and it's my first tank so I don't know a lot of this stuff. Hanging it from the ceiling is a possibility in this spot, but I was worried it would swing too much, plus it's more difficult to remove to change bulbs etc.

Those are NOT waterproof endcaps. If you did have waterproof endcaps you would have to do an extra step (unscrewing the endcaps) before you could remove your bulbs.

With your setup up you can pop the bulbs in and out with just a twist, which is convenient, but also risks letting water in. See how the metal collar of the bulb and the endcap slot are completely exposed?