It absolutely is not needed with the actual Lucas formula. On top of that, depending on your strain, doing so could burn your plants at worst or cause you pH issues. A lot more things can go wrong trying this than can go good.
Have you tried Lucas formula as written for a grow? If so were you happy with the results?
Looks to me like you are going to get some nice fat buds, bud. Not to worry.
One point though. The 0-5-10 is not a "veg" formula. It is a floro light formula. That is why you had the yellowish leafs before you went to the 0-8-16 formula. You had deficiencies. Anytime you are under that 1000 watter you should be using the 0-8-16 formula.
Here is a link to an ask Lucas thread, there are excellent explanations in here...http://www.cannabis-world.org/cw/showthread.php?t=892
There are a couple of refinements to the original Lucas "method" you could try on your next grow. Both of which are described in the the ask Lucas thread. One would be to veg with the GH recommended 15-10-5 formula then switch to Lucas as you get into flowering...but be aware you will get more stretch this way. The second would be to switch to FloraNova Bloom instead of the 0-8-16 formula. It is the same formula in a single bottle plus some humic/fulvic and L-amino acids (or if you prefer you could just add 1 ml per gallon of Florolicious Plus to the 0-8-16 to get basically the same thing).
Sorry if I rambled too much. Good luck.