Hello,
Yeah, unfortunately, the Reptiglo 10 flourescent tube bulbs are just not doing it. They either cause eye problems if enough bright white light is not used or they are too close, or they are not providing adequate UVB emissions which is your case.
The wavelength that they put out is not conducive to D3 synthesis, so, over time their bone density & calcium levels will fall because she has not been able to properly absorb her calcium.
I totally agree, if your tank is large enough then most definitely get a Megaray, they are the best. That is all we use.
Do switch over to the liquid calcium for awhile though, it will help tremendously!
Let us know how she is doing.
Tracie