No new nutrients added, but getting nutrient burn?

Good morning all,
Checked on the babies this morning and noticed some yellow tips, slightly curled leaves, and some dark almost "alligator skin" looking areas. It looks like nutrient burn to me, however I didn't add any nutrients when I watered last time 2 days ago? Only
pH adjusted water (6.5)? The babies looked good up until this morning? Any ideas?
I'll try to post some pictures later.

My grow info: (because I know you'll ask! LOL)
Small cabinet approximately 5 square feet, in early veg stage approximately 4 weeks from bag seed. (I know, bag seed??, why waste my time? I'm working out the kinks before getting "My Precious" seeds.
1 90w LED UFO
1 homemade 5 CFL light box (5-1600 lumen CFLs @ 6200K) planning on building and adding another of these, 8000 lumen in one square foot!!
Room stays about 85 degrees F.
Using a homemade modifed wick/flood and drain system filled with Miracle-Gro Perlite.

I think it's the damn MG Perilite (why do companies add so much crap to their products?) , but I don't understand why it would take so long for nutrient burn to become evident in the leaves? I'll flush the system when I get home, I know that should fix it. Anyone got any ideas on the lag time between nutrients added and nutrient burn becoming evident in the leaves? It's been a week since nutrients were added.

Sorry for the long post, just trying to give you the info you'll need to draw some reasonable conclusions!
Thanks

If you are using MG soil then overwatering will release the nutrients that in the soil faster and burn your plants. If this is the case flushing will just make it worse.

well the yellow tips is nute burn. i avoid the mg logo like the plague.

the downward curving and alagator skin is usually a sign of overwatering.

the downward curving can also be light seeking behavior if the stem is getting alot of light from the side.

dragon skin if i recall can sometimes be related to a buildup of some heavy metals. but this one is fairly uncommon, unless u live near someplace heavy.

MG potting soil isnt too bad. the long term feed shit is whack.

I guess with MG you have to be a little smarter than the soil. Apparently most people here arent. MG is a great soil (#1 selling soil in the world) But people water the shit out of it and wonder why there plants are burning.

bigv1976 said:

I guess with MG you have to be a little smarter than the soil. Apparently most people here arent. MG is a great soil (#1 selling soil in the world) But people water the shit out of it and wonder why there plants are burning.

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So, perhaps it's the actual wick system? I top water the plants with a gallon of pH adjusted water, approximately every three to four days, the excess water drains into the resovior where the wick system takes over and keeps them moist over the next three days or so. I'm using nesting 15 liter storage totes, the plants are potted into individual peat pots then placed in the upper container with MG perlite only.

.[/QUOTE] dragon skin if i recall can sometimes be related to a buildup of some heavy metals. but this one is fairly uncommon, unless u live near someplace heavy. .[/QUOTE]
My name is MASS LOL

u gots to give dem roots a bit of a dry cycle.

encourage root growth, a bigger root mass will help difuse the problem

NOWitall said:

u gots to give dem roots a bit of a dry cycle.

encourage root growth, a bigger root mass will help difuse the problem

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Yeah, I understand that, but I was thinking the straight Perilite would give the roots enough air space to get the oxygen they need.
Perhaps I should pull the wicks out and go with a straight flood and drain system? I have to go out of town often for work, the ease and peace of mind of the wick system was very appealing for that reason.
Any advice from people who have used this type of system and their experiences would be VERY helpful.