please help, bottom leaves are sick, tops healthy, curling,brown, crunchy,spots

thanks everyone for taking your time to check my thread out. my plants have been in veg now for about 5-6 weeks give or take. however, the bottom part of my plant has been looking nastier everyday. my buddy says it's fine because the bottom part of the plant doesn't matter, and he's been growing for a number of years now. but i would like to get a second opinions from everyone. now the top of my plant looks beautiful and i couldn't complain. the bottom leaves are curling, with brown and some yellow spots to them. some have holes and pieces falling off the plant. and these leaves are hard and crunchy. i don't use tap water, however i do use a filtering machine that automatically set's the pH level to 7. it's a machine called kangen water (www.kangen.net) i don't use cal-mag because it doesn't mention anything about filtering anything but chlorine and just adjust your water for acid and alkaline purposes. i have included some pics to give u guys a better idea to what I'm experiencing. thanks again everyone and please give me your opinions and comments.

I'm in a 4X4X7 grow tent, medium: light warrior and happy frog, T5 46 lamp,4" encline fan and 12" oscillated fan, carbon filter
Edit: nutrients im using triflex base&grow, additives are superthrive,liquide fish, diamond nectar,and sub-culture m

That's probably a mild Phosphorus deficiency. The big plant looks wonderful.

yea the those bottom leaves are coming from the the same big plants, they look great, but underneath the beutiful leaves on the bottom are those nasty leaves.. my buddy thats been growing says its normal, it just the leaves that arnt getting light.. but i want 2nd opionions

Here's a pic of a leaf with P def:

View attachment 1316350

Now, the second pic looks like this but the others less so. There are rare situations where a plant can be burnt and deficient at the same time, most often when there's too many micronutrients. You may want to hold off on the Superthrive and any additives you're using for reasons other than NPK awhile.

no doubt overfertilized. back off nutes about 25% and they will be fine.