Recommended Daylight CFL Equivalent Wattage?

I'm doing table top macro in a home made light tent using 100W equivalent CFLs in articulated arm lamps clamped to a plywood sheet on which the tent sits.

The lights are right against the sides/top of the diffuser material (thin white fabric hand towels).

I don't believe I'm getting enough light. I'm shooting [at a defunct gnat] at f8 in aperture priority at ISO 100. The lens is a Tokina 100mm macro on a full set of ProMaster extension tubes. I'm getting .50 to .60 sec exposures.

There's a certain amount of flex to the floor, and I can see camera movement, not from the tripod, but from the floor itself.

I'm using DSLR Controller on an ASUS tablet to do focus stacking. I start the stack and [try] to walk away as gently as I can. I of course have no control over ambient noise/vibration in the apartment. I can see certain frames seriously out of focus, due apparently to movement.

Are my bulbs not powerful enough; is my ISO too low? Diffuser material taking too much light? All three?
It seems that my shutter speed is too slow for the conditions and I'm looking for a way to ameliorate that without going to flash.

It's difficult to be exact without seeing your setup. However, I would suspect your hand towels are much too dense and block out too much light. I purchased an inexpensive light tent and the material is a porous, synthetic, silky like material that is very thin. I use a couple of small LED spots to light most small work and that helps. But I still need a flash with diffuser right on the subject for really close work. You may have to up your ISO or find a better material. And depending on your subject, you may need flash to fill in the shadow areas.

Grand Dad wrote in post #18305729
It's difficult to be exact without seeing your setup. However, I would suspect your hand towels are much too dense and block out too much light. I purchased an inexpensive light tent and the material is a porous, synthetic, silky like material that is very thin. I use a couple of small LED spots to light most small work and that helps. But I still need a flash with diffuser right on the subject for really close work. You may have to up your ISO or find a better material. And depending on your subject, you may need flash to fill in the shadow areas.

Since I posted the question I have:

• upped the ISO to 400.
  
• changed the diffusion material to thin white packing foam from OfficeMax which I'd previously used for a flash diffuser.
  
• added another similar lamp with a 100w equivalent CFL.
  
• ordered a couple of 300w equivalent CFL.