question about recirculating dwc

will i want that ppm in the elevated reservoir, or half strength or something? No I run full stregth in the controller res, the one that sets the level

since the water is constantly recirculating, how often is a complete change of water necessary? I do them every 7-10 days

or do you just top off the reservoir daily? In Flower you should be adding water daily, at least I have to


i plan on running six 5 gallon buckets which i will fill up with 3 gallons each. I run the same setup, 6 buckets with 7" of water (I wanted the baskets a few inches away, that is about 2.5 gallon I think.

here... clipped from GH website, maybe this will help.:thumbsup:

LET ME TRY THAT AGAIN...OK, HERE...:thumbsup:

How can I properly maintain my hydroponic nutrient solution?
Reservoir maintenance is the routine task of keeping the hydroponic nutrient solution in the reservoir from becoming too strong or toxic as the water is being evaporated and the nutrients within the solution are taken up by the plants.

Simply put...
Top off daily with *half strength nutrients, alternating days topping up with plain water. Change the entire reservoir with fresh solution every ten days to two weeks. (*half the strength of your current new reservior starting strength)

Why should you?
One problem in hydroponics solution maintenance, as water is being taken up by the plants as well as evaporating out of the solution, the concentration of nutrient salts in the solution becomes gradually stronger, sometimes to the point of certain elements becoming toxic to the plants. The TDS will always become stronger as water is taken away from the solution.

Another problem, is that hydroponically grown plants will take up what they need as they need it from the nute solution. A nutrient solution left alone will end up lacking key nutrients, with a build-up of *toxic levels of other key nutrients. *Toxic in the solution, as well as in the plants.

The only way around these problems for the average hydroponic grower, is to practice sound reservoir topping off procedures. The most widely accepted maintenance method, involves daily topping off and routine reservoir solution replacement. IE: Topping off the reservoir daily with a nutrient solution which is half of the current new reservoir strength, alternating days by topping off with plain water and finally, changing the entire res solution at least every two weeks.

Changing the reservoir solution every two weeks, will give the plants a fresh and well balanced nute mix, which has not been altered by the plants nutrient uptake.

*Many scientific studies have been performed, which demonstrate these facts by GCMS testing of the nutrient solution contents and the nutrient salts contained within the actual plant tissues, as the plants "take-up" the specific nutrients in the solution.

Metaphorically speaking...
Plants will take up excessive levels of some nutrients, leaving the solution lacking in certain key nutrients. Just like a puppy would make him/her self sick if it were allowed to feed from a bottomless food bowl, plants grown hydroponically can harm themselves with nutrient deficiencies, lockouts and overdoses, if allowed to continue feeding without some control over whats available in the "food bowl".