New..having a prob any advice?

hello RIU this is going to be my first real grow op im at about almost 2 weeks have many seedlings started and taking off nicely..iv been doings tons of research and would like to narrow what my probs really are..in the pics you see one plant where the edges kind of curl slightly also another has yellow dots and the worst one of them has yellowing dots and seems to be dieing Thanks for any advice/correct information

1) Get the light closer
2) Water them because they look dry
3) Invest in a water pH tester and pH the water to the 6.5 range
4) They are going to need nutrients soon

thanks the lights are about 4-5 inches away watered them after i took the pics that was 2 days without water could still see moisture in the cups but i waited to advoid overwatering i do have a ph tester ph is between 6.4-6.8 and they just got fed AN tarantula and pirahana 3 days ago this is my frist serious grow but i have done tons of research any other ideas??

??any ideas??