Hey ECOBANE, I am some what new at the growing thing here. So do not take my advice very serious. You should make sure that your res. is 120% light proof. The blue walmart tote is not very light proof. I add a tsp of 3% walmart or walgreens brand h202 per gallon 2 days after I change out my water it helps keep the slime or whatever at bay. I had a friend that had slime, clear or white will usually clear up with the h202 you get at the hydro store. If the slime is a grayish brown color you are pretty much s.o.l. my friend ended up using a tsp of bleach per gallon to clear up the grayish brown color slime. Make sure you keep your lid closed as much as possible and clean out the res really really good between water changes.
I tried the 6 way manifold at first then trashed it and switched to an air pump and bubble stones and have been working out very well. But if your set up is working then keep up the good grow.
Good luck.