22" T5 for 4x2x2

Since I just finished my 4x2x2 tanks, I needed to figure out which bulb/fixture combo would work best for this size tank.

Well, quick and short, I'm going with the 22" even though the tank is 48" in length. This is less than half, but it was the only way to get some areas to have a UVI level of 0.

Only about the furthest 3-6 inches of the tank have a UVI of 0 with the 22" 10.0 T5. So it's really quite a small percentage when taking into account the whole enclosure.
With the 34" even the farthest area from the bulb had a UVI level of 0.5-0.6. Even without a reflector on.

So, If ones goal is to provide a truly proper UVB gradient in a tank, it appears that for 4x2x2's the 22" bulb is the way to go, not the longer one.
And this is of course with the tube almost butted up against one side, I'll add pictures tomorrow.

-Brandon

I like the 22'' because it is long enough for a dragon to bask evenly under while still providing a good gradient as you said.

Yeah I agree.

I typically hadn't been using the reflectors since in my other setups it's not necessary. But I decided to get one with the 22" fixture this time just in case.
Noticing a strange occurrence, my UVI levels are actually higher without the sunblaster reflector attached. I'm not 100% sure why, but I'm assuming it has something to do with the semigloss white enamel paint I used. Either way, i get higher levels without the reflector... at least in these tanks.

Gonna have to do a few tests and try to figure out if it is the paint, or if the reflectors are just bogus.

-Brandon

Did another little test today. Nothing super conclusive but the reflector definitely isn't adding any strength to my setup. Ran it all day with reflector yesterday, and then ran it all day without reflector today and the numbers are identical between both days.

-Brandon

Definitely odd. At least you are able to test it out to know what you’re working with.

If I have some time this weekend I'll setup a little rig to test the reflector and test the paint I used. If I had to guess it's simply the white paint of the enclosure acting as a reflective surface.

Makes me wonder if melamine works the same way. Or any other glossy or semi-gloss surface.

Either way, since it doesnt appear that the reflector hampers the output, it's probably better to just be safe than sorry and recommend the reflector as we typically would.

-Brandon