Yeah they are a bit tall i would add a bit of soil to them to keep them strong. And the tips are yellow from the nutes you are giving them. At this stage they should not need any nutes really at all. Especially if you are using a hot soil like happy frog or ocean forest etc. And when they do need to be fed you should start them at 1/4 strength and work your way up to about 3/4 strength. The foxfarm feed chart is way to concentrated.