First time hydro

That's not true. This here is 4 weeks old under 3 17w flouros.

 

I hate to say it, but the items you can't change are the problem.
 
Get some 2'' net cups, starter plugs, and and some clay pebbles for next time and you'll do just fine. The styrofoam cups will limit how the roots can grow, and those stones aren't allowing for enough space for roots to make their way through the spaces between them.
 
This was grown in a small bubble bucket with a 13w desk lamp above it:
 

Less light than you are using, but the growing container and medium are appropriate. Once you get your immediate problem solved, upping your wattage will help you produce a viable harvest.

 

I've only used expanded clay pebbles, so I can't offer any input re: perlite.
 
You can get a 50pk of 2'' net pots from Amazon for just under $8 with free shipping.
 
Read through this thread - it's between an guy who was growing in a small space and I, and it may answer most questions you have:
 
http://forum.grasscity.com/absolute-beginners/1258832-started-out-greatnow-i-have-some-major-issues.html

 

I would read the Bubble Bucket method tutorial sticky at the top of this forum. That styrofoam cup isn't going to do you any good.

 

If I was in your shoes this is what I would do. I would transplant it into a larger container 1-3 gallon with some type of organic soil. Solid black or any other color thats doesnt allow light through. If you want to stick with hydro you'll need a couple hundred dollarsto invest into equipment. Also a good couple days of your time to properly research how to properly run a hydro system. Soil is simple. I would stick with it for now.

 

you dont need a water pump for dwc. Is that air pump in the pic the one u have? If so ur gonna need one abit stronger. since ull be starting from seed you will have two or 3 weeks maybe before the roots reach the water so ull have to hand water for now. Also make sure by that time u have ur nutrients, a ppm pen and also stronger lights. But most of all keep doing more research. That little air pump will do for now but definately get one stronger. you can never have too much air.

 

 
What you need for DWC...
 
Water proof and light proof container with lid.
Net pot.
Clay balls.
Air pump that puts out 1 litre per minute of air for every 2 litres of nutrient solution.
Air stones and air lines to match your pumps output.
Proper hydro nutrients.
Ph down.
Ph up.
EC or ppm meter (£5 Chinese ones are perfectly fine) 
Ph meter (same as above) 

 

Im also on my first grow so i cant give that much advise on nutrients, i use the general hydroponics flora series though. Ull be able to germinate ur seed and and plant it ull have till ur seedling develops proper roots until u need ur nuTrients. once u have proper roots u need everything goldgrower listed.

 

I use a 15 dollar hm ppm meter, it works fine for me.