Scrap it and get a better one . There are basically three types of UV lamps compact fluorescent lamps CFLs , some call them coils , linear fluorescent lamps LFLs , longer tubes , and mercury vapor bulbs MVBs . Stay away from UV CFLs , they aren ' t really suitable . Some UV LFLs aren ' t suitable either , others are . I ' ve explained everything and . You should also read this a r t i c l e H e a l t h H a b i t a t s C a r e R eptileLightingInformation and definitely watch this videoAUu 24 MNO 2 Ho . Long story short CFLs simply don ' t cover a large enough area . They are too weak and too focused , they ' d have to be way too close to a tortoise to be effective , and then they ' d still not cover a large enough area . And like I already said , that mesh blocks a significant percentage of light , including UV , making it even weaker . The point of UVB exposure is to enable vitamin D 3 production which is involved in calcium absorption very important for bone growth . As usual with chemical processes , they are temperaturedependent . Therefore , UV lamps need to be placed in warm spots , not the cold end of the enclosure . With natural sunlight or MVBs you get heatvisible lightUV all in one , which is how it should be . Your table has a good size , but the lighting could use serious improvement . I ' d probably give it at least two basking areas plus a good UV T 5 LFL including reflector , as shown in the linked video .