I really detest those screen mesh lids
>> temptation for keepers to simply sit all the lights on top = bad
....
the mesh will shade up to 35% of the UVA and UVB ... see *
>> warm air created inside the viv by the basking globe and /or heatpad and /or CHE is immediately lost to the environment ==> you must use much more wattage (electricity) to attain the desired basking spot, warm zone and cool zone temperatures
>> very hard to produce a stable thermal gradient and microclimate see above.
>> very easy for other pets to get into the viv
I recommend buying a solid plywood lid which has provision made for the basking light and air ventilation.
A solid lid will
>> provide a stable platform from which to hang lights and fittings
>> will insulate the viv from the room environment
>> will force warmed air to circulate ==> less wattage needed to get the same temperatures
>> be other pet proof.
* The amount of UV blocked depends on the geometry of the mesh used in the screen lid , this depends on the mesh pattern , the wire diameter and the aperture see
http://a0.leadongcdn.com/attachment/klijKBpqRijSpjlrinSR7ww7fgzb73p/Woven-Mesh.pdf
Is very simple geometry problem to calculate the open area for PLANE mesh , bit more tricky for twilled mesh pattern , Dutch pattern and twilled Dutch patterns.
No 2 plane mesh blocks 30%
No 3 plane mesh blocks 35%
No 6 plane mesh blocks 38%
No 12 plane mesh blocks 38%
No 16 plane mesh block 44%