So I have my MVB on top of my screen, the mesh is very fine / small, would it make sense if I just grab some wire cutters and cut a hole just around the bulb to let in all the UVB?
That would allow more of the UVB through which is usually helpful. Which MVB (and wattage) are you using and how far is it sitting above the highest basking area?
That bulb has an optimal UVB output between 10-14'' above the basking area without a screen. If you cut a hole in the screen, I'd make sure the basking area is built so that the bulb is within that range above it. The screen may block around 30-40% of the output so through a mesh top I'd keep it at around 8-10'' or so. This is based on testing from uvguide.co.uk. It's also noted that the decay is rapid with that lamp based on the test model so I'm not certain of the current output of your lamp without testing it with a UV Meter. I'd use that range as a starting point though.
This is my second purchase of this MVB when I first bought my beardie.
I was overall happy with this but I bought this one 2 days ago.
I had also considered switching to a reptisun 10.0 tube but I have these Natural Geographic UV sensor cards that measure the intensity of UVB ( Low, Moderate, High) and when I turned on the reptisun tube it didin't emit any UVB, just light. So I went back and exchanged it for the MVB.
I'll keep it at this height for now, but I have to go back to the store so I can get a deeper fixture as the bulb iself sits on the screen top.
The national geographic cards aren't very accurate unfortunately. They tend to pick up on UVA rather than UVB. A UVMeter is the way to go to get accurate measurements but they are relatively expensive. That's why I rely on the tests from uvguide.co.uk to determine appropriate distances for each bulb. It will be good to use a deep dome fixture for the bulb if you need it to sit a bit off of the screen top. Alternatively you could hang it from an adjustable stand so it can sit a bit higher off the top of the tank.
This is my second purchase of this MVB when I first bought my beardie.
I was overall happy with this but I bought this one 2 days ago.
I had also considered switching to a reptisun 10.0 tube but I have these Natural Geographic UV sensor cards that measure the intensity of UVB ( Low, Moderate, High) and when I turned on the reptisun tube it didin't emit any UVB, just light. So I went back and exchanged it for the MVB.
I'll keep it at this height for now, but I have to go back to the store so I can get a deeper fixture as the bulb iself sits on the screen top.