Plants keep geting yellowing leafs on the bottem & I can't tell which deficincy it is

[mjisgood21]

Here is the pics.Temps 76*-98* with 3 fans running on high constanly. .05-.05-.05 soil.The soil gets bone dry in 4-5 days usualy.using purified water with a 6.0ph.Nutes haven't relly gave them much(1/4 mixed to a galllon).Maybe once or 2wice.Im using a 150w HPS about 10" or so from them.

 

[nickfury510]

nitrogen....

 

[stupid]

It could be nitrogen toxicity.
Check your ph.

 

[spiked1]

It could be nitrogen toxicity.
Check your ph.

Definately not, there is no sign of clawing.
But do check the PH.

 

[CanadianBacon]

too much nutes

 

[George W.]

If your Temps Fluctuate that much it is not good. Try to keep the temps in the low 80 if possible. They are definatly showing signs of burn. I just had a similar problem in my opperation. When the soil drys out salts build up and this salt buildup can burn the plants. you should get a soil moisture meter. You also have to check the ph because nute lock out or burns can occur if the ph is off. They might look like they are showing sings of a defeciency but this diagnosis can be miss leading. Check PH (adjust if nessasary) and keep the soil a little more moist and the problem should correct itself.