Spectrophotometry: shifting absorbance curves vertically so isosbestic points match

We're measuring reaction kinetic parameters of a hydration reaction (Co complex) by measuring the absorption spectrum a different time intervals, and calculating the ratio of product to reactant by comparing the absorbance measured to the absorbance spectrums of the product and reactant in pure form. Water baths at 6 different temperatures were tested and for certain graphs, the results are coherent, with curves meeting around the isosbestic point (where the absorbance of both product and reactant are the same, first graph). However for certain graphs there is a significant vertical shift on certain curves which renders the results incoherent (second graph)


I had the idea to shift the stray curves down to match the isosbestic points of the product and reactant, as this should technically be constant whatever the reaction progression (at a given concentration). I realize this will render the use of the Beer-Lambert law pointless as we are completely fabricating our results, however what is important is the ratio of product and reactant, relative to other curves, which will be conserved, and these will actually be comparable once the isosbestic points match.


I just wanted some outside input


-Is this unscientific? Will my TA wonder what the hell i've done and take points off, or is this process justifiable


-Should i just process and present my data without trying to correct the error.


-What could this baseline error be caused by? since the errored curves seem to be shifted up, i'm suspecting condensation on the cuvette walls increased the absorbance, as the water baths went up to 50 degree. Although I dont remember noticing condensation on the cuvettes.


Thank you for any input.


[![Good Plot](https://i.stack.imgur.com/e6INL.png)](https://i.stack.imgur.com/e6INL.png)
[![Wild plot where things whent wrong](https://i.stack.imgur.com/TUThy.png)](https://i.stack.imgur.com/TUThy.png)


