Many people talk about not swapping their reservoir the entire grow or at least once when flipping.  I'm trying this out. Obviously the concern here is the buildup of unused nutrients causing imbalances and nute lock.

 I have two plants that are about 2 months old growing in 5 gallon Hydro buckets.  I have only changed the reservoir once when flipping to flower. I use Master blend throughout the entire grow.

Here's what I noticed when not doing the weekly res change. Right around the 7-Day Mark I would notice that the EC would suddenly rise higher than what it was the day before.  And the pH will drop suddenly down to something in the 4 range.  The water level is usually at the 3/4 mark.

If the plant looks hungry or the ec is low I will add nutrient solution and fill it up.  I aim for a final ec level of 1 (with this strain).   If the plant is not hungry and the ec has risen I will top off the res with water that was left out.  

Whether i add nute solution or water, this seems to bring balance back to the bucket and I can carry on for a few more days.

Do these results sound typical?

My previous method with dwc-  after swapping to a fresh reservoir (once per week), I would pH it down to 5.8. The next day the ec would usually lower a bit but the pH would rise to 6.8.  I would pH down to 6.0.  It might float to 6.3 the following day but the ph would then stabilize for the next few days, then the next res change.


Anyone NOT change their res every week?