Need help please.

This is my first grow, my leafs are starting to turn yellow and the tips are brown. I water 20 minuets 3 times a day, is that to much and making my leafs turn yellow. please let me know what you think. thanks.

Are you using nutes?

i just added a little nutrients today.

dose this look like im over watering?

how old are they?

You can't over water a hydro system... I would wonder if your roots are getting enough water, what is the normal water level of your container (if any level is kept). Hydroton doesn't hold water very well. I was going to use hydroton on my first grow but couldn't figure out how to ensure the roots where getting eough water when it was a little guy. So I went to rockwool and havn't tried hydroton again, yet.
Or you are burning the little guys, heat maybe?

they are about 4 weeks, so should i keep the waterpump on all day? what are your recomendations?

I would think so, at least untill they get a little longer roots. I don't know how deeep your container is but you shouldn't need to do that for much longer. Your roots should be getting nicely developed if not now than very soon.

so leave the pump on all day untill the plants get alittle more established. i just raised the light 4 inches so it wont burn the leafs. thanks for your help smokertoker.

make sure it's okay for your pump to run 24/7. I don't want you to burn that bad boy up. It may want a 30min break or something. I don't use water pumps in my hydro setup so just make sure your not going to hurt your little pump friend.

ok thanks.

looks like lack of nutrients. I am growing in rockwool and my leaves did the same thing because I followed everyones advice of no nutrients for the first two weeks. Well little did I know that is generally for soil. When I went to the local hydro store they told me that since I wasnt using any nutrients they began basically eating their leaves and watering them without nutriends actually strip the nutrients that they do have. I bought nutrients and the they started growing a fresh new set of green leaves and never had the yellow problem again.

MORE NUTES!

thanks, i added nutes yesterday, so i will wait to see if there is any changes.