DJ - I have a DWC using the same nutes that you are. Here is what i have seen first hand, at first i was using the Pure Blend Pro Grow (which is very dark straight from the bottle and kinda gritty), during the veg stage you are using around 1oz per gal of water, the same company makes what is called Triflex. The difference between the two is pretty simple, the Pure Blend Pro Grow is a One part nute and the triflex is a 3-part nute mix. When i use the Pure Blend Pro Grow in my DWC the roots on the all the plants will get this brown, slimy, stuff hanging on to it, you can simply spray the roots to clean them, but what your doing is simply removing the nutes that were in the solution to begin with. When using the triflex there is no buildup like that, and your res will stay clean. Now the only thing i dont know is if you keep using the Pure Blend Pro Grow in your Hydro if it will hurt the plant and equipment or not. I did notice that the plant roots are darker than what they use to be since i put that into the DWC.

With all that being said, what i have decided to do is use the Pure Blend Pro Grow for my soil plants and the triflex for my hydro plants. Since i have been using the triflex line i havent had that build up on the roots or any problems.

Hope that helps.