Your clawing should be gone by today . But clawing is a sign of excess nitrogen which isn't your problem or wind burn which might fit your problem I don't know if you have a fan directly on them. Far as yellow spots that could be anything because your not feeding them which I tilt my hat to you for that but when you told yourself you wasn't going to feed them you also was suppose to tell yourself you still need nutrients. Because your method is harder because you waiting for the deficiency to show and you have to address the deficiency immediately before it gets worst but you have to first know how to identify the deficiency you having. So I recommend if money is tight go to a local garden store and get some basic start, veg,bloom nutrients but general hydroponics are cheap on Amazon for about 20 bucks can get the basic trip to finish the grow and give them a light feed when it arrives . Amazon ship 3days anywhere in U.S so