No bugs to be seen, but plant is dying of something, please help if you can

[erwqew]

This is something that has surfaced just recently and my plants are slowly dying. They are clones in a bubblephonic system. At the moment I am back to straight tap water PH'd to 6.0. Rez temp and room temp are both 70ish.

I have loked through many , many areas on this website but have yet to find out what is causing my issue.
It should be mentioned that even thought I cant see any bugs I sprayed em down today with a soap solution from Home Depot.

If I find out the problem here I will certainly post the solution with pics for others to see.
Any help is greatly appreciated.

Thanks in advance for anyone with help

 

[Captain Kronic]

I am not an indo guy but, ifin I were, I would have a look at the roots on one of those girls. I say that because I don't see anything else to point at w/the info I have.
But I am not an indoor grower, not yet that is!

 

[alocer]

just cos u cant see bugs it dont mean there 100% not there mate act fast i would iv been in ur situation before just get a good systematic bug spray an spray em.. if i see leaves with holes in em i spray em and 9 times out off ten it sorts it... another thing thats massivly overlooked on these sights is the fact it could just be a weak crap plant ?? i had a period before where growin was pure headwork always problems soon as i grew afghan which are really hardy resiliant plant and not 1 problem since cos iv never bothered growin random shit again ?? always make sure u grow a tough fucka that aint efected bye a little drop in ph or slight temp issues and u wont have to pickle ur brain for hours on the net then mate

 

[Batcave]

I used a "plant safe" insecticide soap from Home Depot a few months back and it almost killed one of my white widows. I dont have any pics of it but it looked like your leaves (kind of burnt), just less droppy. Don't know if that is your problem here, just a thought.

BC