Need help on hydroponics

[OutLaw]

my plants are turning yellow at the top but im not sure why,some leafs are looking like there dieing and i also wanted to know if i should put water from my water turtles into my resivor tank for better growth please hit me up wit some tips on this subject

 

[McBudz]

can you upload a pick of the problem leaves?

have you checked out the pictorial here.

Not sure what a water turtle is.

 

[OutLaw]

i cant load pics but the best way to discribe it would be that the bottom is green but as soon as it hits half inch before the top it turns yellow.
then i got some turtles that are ment for water and i was wondering was if i can put the water they live in into my resivor tank cus some where i read that gold fish water was good for the plants

 

[Stix]

what kinda sytem are you using?
what kinda nutes? What strength? (PPM)
how old are your plants? are they in veg or flowering?
What is the PH of your water?
What kinda lights are you using?
How close is your light to the tops of your plants?
What are your room temps?
How long has your problem been happening?
When was your last nutrient change?
Have you done anything differently recently?

Answering as many questions as possible will make it easier for us to help you.