18" vs 22" vs 34" Reptisun HO 10.0/Arcadia 12% T5

I have made the decision to scrap my MVB (it will be my "travel bulb"), buy a dimming thermostat, T5 light fixture and hallogen spotlight bulb to better regulate the temps and UVB in my terrarium.

Right now I have a front-opening exo-terra 36"x18"x18" and have every intention on getting a 4'x'2'x2' front-opening terrarium at a show in October.

So, tht being the case, I'm stuck on what size of fixture and bulb I should get - I will most likely be transferring this light fixture to the 4x2x2 enclosure in a few months.

Sooo... I don't want a 34" because that would not provide an ability to get out of he UVB in the 36" enclosure (other than going in his hide), so it is pretty much between the 18" and 24".

In his current viv, an 18" would cover half of it, leaving an 18" "off" zone. A 22" would cover nearly 2/3 of it.

I'm leaning towards the 22", in hopes that I may not have to upgrade to a larger sixe when transitioning to the 4x2x2. Any thoughts? Is the 22" what I want?

Thanks

Yep, the 22'' should work well. http://www.lightyourreptiles.com/22-t-5-ho-fixture-high-output-with-arcadia-d3-12-ho-bulb/

I have also used the 36'' in the same tank and found that you can still produce a pretty good gradient by moving it to the front or back of the tank. The 22'' is long enough to cast a beam of UVB that will allow for even basking in any tank though which is ultimately the goal.

Good deal. I just ordered a 22" arcadia 12% and this fixture + reflector: https://www.amazon.com/Carolina-Custom-Cages-Standard-Reflector/dp/B00K2AY8EW/ref=sr_1_1?ie=UTF8&qid=1534443643&sr=8-1&keywords=22%22+T5+fixture

I'm going to velcro it on the back wall (at the top) of the enclosure, with the hallogen spotlight bulb hanging from above for basking temps.

How far should I have this set-up from his hammock? Does 10" sound right, or should it be more in the 12"+ range?

Thanks again

FYI, it's difficult sometimes to get the 34 inch to fit in a 36 inch tank, because the plug in is on the very end making it about 36 inch long that you are trying to squeeze into the 36 inch tank. I have two of them. One I had to put on a diagonal into the 36 inch terrarium to make it fit.

I would want to test that fixture before recommending a specific distance. It looks somewhat similar to the one from ReptileBasics. I've tested that one and while cheaper, it has an inferior reflector which cuts down on the effective distance. If this is the case for this fixture (I don't know without testing it using a Solarmeter) I would err on the side of mounting it closer but still providing areas away from it. 8-12'' is probably fine given there are areas with little to no exposure available. They can tolerate areas with higher UVB exposure at times. They are good at self regulating so just watch and see how much time is spent directly under the bulb. If it is avoided then try raising it a bit higher.