Insufficient light

Bulbs are self sufficient units. Cut back on the water (bulbs will rot if constantly wet) and any fertilizer too.

so too much water and not enough light?

I'm new to this forum, but hoping to get more aquainted :)

I know I'm late, but has the problem been solved? if not...

I would have to say once every other day is too much water given the type of soil. From what I can tell a standard potting mix (lots of compost/peat moss and negligible amounts of perlite). For the future, i would mix equal parts potting mix and perlite. Perlite floats to the top over time, but for temporarily indoor plants i let it slide. I had a florists "stargazer" lily from valentines day last year, I let the pot approach dryness when flowering and let dry out afterwards. This year I am starting lilies and dahlia's indoors...since the lilies and a few dahlias broke dormancy (I guess that's what I get for a bargain price?).

I don't know anything about baby bio, nor how lilies in particular respond to fertilizers....but if it is really high in nitrogen that could be the reason for weak growth. Some plants respond with lanky, weak growth and even abort blooms with enough nitrogen.