As for nutes. I use these for a small tent grow. Might even last a few. https://www.amazon.ca/Technaflora-Recipe-Success-Starter-Kit/dp/B0001XGP32
I use this ballast: http://www.ebay.com/itm/1000-watt-1000W-digital-HPS-MH-Grow-Light-ballast-120-240V-400W-600W-1000W-SUPER-/290686665975?hash=item43ae4684f7:g:LdwAAOSw-7RVC2ZI
With a Hydrofarm reflector similar to this: https://www.hydrofarm.com/p/RD8AC
And Technaflora nutrients: https://www.amazon.com/Technaflora-Recipe-Success-Starter-Kit/dp/B0001XGP32/ref=sr_1_1?ie=UTF8&qid=1490575064&sr=8-1&keywords=recipe+for+success
The ballast is adjustable between 400/600/1000 watts. I use 400 watts for germination / initial growth, and then up to 1000 watts for fruiting. It also doubles as a space heater for winter hydroponics (DWC). :)
I would ask here. You should be able get some help there. Its a great site for info in general. Do you know the ph of your water your using is? If the ph is too high or too low you could be locking out nitrogen which might be why your leaves are yellowing. You can get the drop ph test kit at pet store like petsmart and they'll also have ph up and down but you can find it cheaper online.
As for nutrients MG is fine it will work but start low and gradually increase the amount you feed or you'll burn the plant. If you're looking for something better check out this
The following nutrient kit would be good for you. It very easy to do and very adaptable to the situation. It even comes with a recipe... for sucess!
I think your lacking a lot of nutrients.
Technaflora Recipe for Success Starter Kit https://www.amazon.com/dp/B0001XGP32/ref=cm_sw_r_cp_api_ut6gyb3P5JB01