Grow Mediums Relationship between Reservoir size and nutrient concentration

[kunkgrow]

Relationship between Reservoir size and nutrient concentration

Hello growers.

I'm on my first hydroponic (rDWC) journey and still have many questions and problems arising, learning every step of the way.

Lets picture the following scenario to better understand this questioning:
Imagine two systems
One that holds 40 gallons in total with only 4 plants.
One that holds 20 gallons in total with only 4 plants.

Now lets say you run your nutrients with 500ppm on each, same dilution.

Is it possible to assume that the 40 gallon system will potentially burn your plants when the 20 gallon system doesn't ?

Ok, you have the same concentration on both, but on the 40 gallon the plant has more available due to the larger volume, and even though it drinks at the same concentration, it drinks more and more without ever bringing the EC/ppm down due to the higher availability.

Do you see where I am going? Does it make sense?

 

[woody]

I can see your reasoning but i dont think so no. A plant will only drink so much according to its age, size, rootmass, environment, maybe even genetics etc
Even so in dwc the system will always be kept topped up so they always have a full res to drink from so its kinda like the plant has unlimited water no matter what size the res.

Im pretty sure if ppm and ph is stable meaning the plant is getting the right amount it cant burn no matter how much it drinks.
Unless theres more to it than i understand?
Maybe someone else has a different theory

 

[Muddy]

When an RDWC system is running properly your ppm should show a steady drop between system changes, assuming you're not replenishing via a top off res. Is the ppm dropping the same in both systems? All are the plants the same strain? Same lights? The volume of water isn't going to matter.

 

[KushNFT]

The larger the res the easier it seems to be to control nutrient concentration and pH but the more expensive res changes get.

 

[Muddy]

The larger the res the easier it seems to be to control nutrient concentration and pH but the more expensive res changes get.

Once you get the hang of it it's pretty easy to keep a big or small system stable in rdwc, especially if you use a top off res to replenish the system. In general rdwc systems use less nutrients and require less frequent system changes, so they are actually less expensive to run than other forms of hydro that require weekly changes. I rarely exceed 500 ppm(500 scale) in full bud swell, which is at little less than half strength, and do system changes every 3 weeks.

 

[kunkgrow]

My rez is so big for my plants it can go for weeks without even a small dent in water level or nutes concentration. Plants are small autos though. I've learned my lesson, after this run I will redesign the setup for ebb n flow table

 

[kkeniff]

No thats not how it wrks...but if yur not growing photos where u control veg time yur just spending too much on nutes/time etc..

 

[Muddy]

My rez is so big for my plants it can go for weeks without even a small dent in water level or nutes concentration. Plants are small autos though. I've learned my lesson, after this run I will redesign the setup for ebb n flow table

I love rdwc and couldn't see myself growing hydro any other way. I'm going to be cleaning out my veg system on Wednesday and am planning on taking some pics and posting them up. It's a DIY system I build using two Rubbermaid Brute 14 gallon totes. I'm liking it so much I'm thinking of building one for autos using two 20 gallon totes. They are a good size for growing 2 plants per tote. It would run with less than 30 gallons of solution, which should be good for 4 plants. I can build it for under $500, half of which will be the chiller. Depending on what strains I run I think it can yield at least a pound per grow. Take a look when I get it posted. I think it's a good design and you might like it.