Typically a sign that roots are too wet (lack of oxygen) and/or root temperature is too high.

thinking it must be the root temperature. Its in a clear tube dwc with 4 plants (t5 light) about 6-9" tall, two air stones, not much there for roots but what is there are thick diameter wise, water is just below the cups about .5 inches, ppm is 1050 in 4 gallons of water, and water temp reads 68 F. I have been fighting the last few days with the ph and I'm guessing this was causing the rapid rises of ph.

Morb1lee,

I agree with hex2006 and it looks like you are taking
corrective measures.

First see if you can get the water temp down (either moving
the light up or just put the tube against something conducive to heat vexing
aka a metal table or cement floor). I would recommend removing the plants from
the clear tube, if possible, maybe by spray paint or upgrading to another type
of tubing.

Secondly, I would suggest a root wash to take care of the
current slim while correcting the problems. Normally watered down mixture H202
for an hour or buying an oxygenating solution.

Also, could we get a pic or imgur of the setup?

As a side note, pH up and down can be cause by a lot of
things. Can you give some background on the pH problem?

I would adjust my ph level to 5.5 and about 48 hours later it would be up to 8.0. I originally thought this was because of having cilantro mixed in with it but it continued after I tool the cilantro out. I moved the light up so hopefully that will help my water temp a little. my steps forward was going to be as, you suggested with, upgrade my container or paint my existing. I am looking to do a different system right now. like a 4 x 4 with a raft or kratky system. i am thinking upgrading my container may happen before i may the 4x4 system for now.

Looks like you have rockwool in the netpot, if its completely saturated that wont be helping the roots.oxygen wise. Do you have plenty of airstones/bubbles in the tub?