Nutrient question for recirculating dwc

I'm doing a recirculating DWC and I've got a big res for the nutes so I don't want to necessarily be draining it every week. My question is, with the water in the tubs being pumped back into the res then back into the tubs after being swirled about a bit, will I need to keep adding extra nutes periodically or do I have to drain and refill? If so, how often do you think this will be required.

Thanks ppl.

If you use General Hydro,or Lucas formula you can grow an entire crop with the first original reservoir by first topping off the reservoir with water and then adding nutrients back to the original EC or PPM level.Most nutrient labels recommend changing out the solution every 7to14 days.I change out every 7 days.

http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm

Thanks Gixxerboy. I'm going to be using the Canna Aqua nutes as it apparently helps maintain a stable PH.

Hey not to be pushy but can I see pics of your set up? I just built a small aeroponics set up (4 plant spots) and I was thinking about making a rdwc set up

gimme a couple of days and ill sort some out.

i am running a under current RDWC and i have a control bucket on the system that i mix my nutes in that way in my res all i have to keep is straight ph'd water.. it is hooked up to a float valve in my control bucket so it maintains my level in the system to... also it doesn't mess with my ppm's in the water circulating through the system it will only lower them if water is added from my res... oh and i save on having to waste nutes too..

I didn't realize that most use a float valve when doing RDWC. I did mine differently. I just pump the nutes into each bucket from a manifold and let it overflow out at the right level. With young plants I take the squirter out of the bucket and put it up in the hydroton to keep the roots wet before they reach down into the solution.

My res slowely drops as the plants drink, but the buckets all stay the same level. Then I just manually add some water into the res. Been working great so far. I also fill the res less with smaller plants so I don't have to waste as many nutes on plants that won't use them up before my 10 day change period.

I've got a float valve to keep mine topped up from the res too (very easy). I do like your idea tho Shafto.


If I hadn't just upgraded my setup I would have gone for this under current dwc just for the fact the water can be drained and fill soo quickly but I am happy with mine. Can't wait to get the babies in there