first hydro grow! pix and opinions

so its been about 2 months now so ive decided id let everyone see my babies and tell me their opinion, i have a question about my resevoir tank too. its built up foam sorta inside along the edges and i was wondering wat that is from and what causes it, and also how to treat it. my kids are 2ft on the left and one foot on the right. idk what the sex is and im not sure how cuttings work. ive heard about taking a cutting and puttin it into 12/12 light and that would determine the sex. ive also heard that males are alot taller than females and that the females tend to be small and bushy. Opinions are greatly appreciated. oh ya, ive noticed some of the old leaves dying off and turnin yellow and the a brown dry color and falling off, is this normal?.....and they all pretty much have 11 leaves on them

looks tidy setup to me. sometimes leaves die off when they are past being effective, its dependant on the strain and the environment, like if a lower leaf isnt getting enough light to warrant it to be there so the plant discards it so its not having to "power" the leaf that isnt pulling its weight.

Adding reflective material might help that also.

I would be taking extra measures for air flow in such a small space like that, mebbe get one Co2 in there also.

The foam is because the nuit in the tank has increased the viscosity of the water and ita heavily aerated, the air is coming out of the water taking water with it (as the surface tension is now high enough to be carried on the trapped air being released). I would also be careful on this point as you can get algae growing in there (Everything is present, nuit, water air and light) cover your tank from the lights and check the foam isnt discoloured indicating something is growing in there.

I could be wrong with all this of course but thats what i would be thinking in that situation, apart from that you seem to have a nice setup.

Mor