It stinks, but not a good stink...

I have had some trouble with my dwc res water smelling. I noticed it when it smelled like a dead animal in the room, and when I looked at my water it was kind of cloudy. I was having pH troubles and used about 3 and one half tablespoons of pH down to my 12 gallons of water to get it from 8.7 to 5.8 when I first filled the res, then had to add more pH down about 3 days later to bring it from 6.9 to 5.6 and after that is when the smell got worse. I grabbed my second tub and filled it with clean water and adjusted the pH the same way mentioned earlier. One day later here I am with slightly cloudy water and the smell is picking back up again.

I was thinking possible root rot, to much pH down, or both. My plant is two weeks old as of today and hoping I can solve this issue. Thanks in advance for those who decide to help!

do a res change? are you using organic nutes?

I changed my res last night in a very clean tub, and I wasn't going to nute it until the third or fourth week. I took a glance at my roots and they are fuzzy white! Very healthy, I don't know what is going on. I was going to add some H2O2 to my water to see if that helps. Thanks!

Sounds like root rot/pythium. Are the roots kinda brown and slimy? If so along with changing the res you will also need to treat the roots or the problem will remain. With the next few res changes I would include 35% H2O2 at a rate of 3 or 4 mil per gallon of res............
Lack of oxygenation will cause this issue along with other anaerobic situations....thats were the smell comes from....

Pumping lots of air?

try using a tea...not exactly sure what you call it but someone posted about it

Thanks for the advice everyone! I went ahead and added H2O2 to my res to see what happens. I'm planning on changing it again either tonight or tomorrow. How do you recommend treating the roots?

I do have a 12 inch air stone pumping and when I got the package it said it would work up to a 60 something gallon tank. Is that enough? I was thinking about getting a round air stone to add to the system to see if that would help.

Thanks again!

More air will be fine.