DWC Bubbler Design Questions

[Filbert]

Hi all, I'm new to the forum, and thinking about building a DWC bubbler hydro system based on some of the information I've gathered here. I have a few questions and concerns that could affect the design, and wondered if any DWC experts would care to lend me some advice.

Here's what I came up with criteria -

1. Uses individual 4 gallon grow chambers, allowing each chamber an adjustable nutrient solution level. (Not nute level, fluid level. I know, sounds weird, but I've got that part worked out)
2. Recycles nutrient solution through entire system as much as possible.
3. Uses reservoir as single point for nutrient change/pH adjustment, NOT requiring changing/adjusting each grow chamber.

Here's what I'm envisioning - (The recirculation parts, bubbler and level adjusting stuff is left out for simplicity)

In this example, each grow chamber will contain about 3 1/4 gallon nutrient solution, and the reservoir will contain an additional 4 gallons.
I've got the recirculation part figured out, what I'm concerned about is the reservoir capacity, and nutrient changes. I'll be able to pump the reservoir out at the same time I'm pulling down the level in the grow chambers, so I'm thinking the reservoir capacity ought to be OK.

So here's my questions -

How long can the plant roots in the grow chamber be exposed to air without getting damaged?
There will always be about 2 inches of nutrient solution even when changing nutes, and the bubbler will remain on. I'm expecting a nute change to take about 30-45 minutes.

Can I replenish the 75% of the system fluids with non-nute pH balanced water, and then add the remaining 25% fluids WITH nutes to the reservoir for circulation/mixing without shocking the plants?

Thanks in advance

Filbert

 

[Filbert]

Thanks Pit, yeah, each chamber is going to have a 24/7 airstone, inlet for recirculation, and a height adjustable overflow for level control. I just left all that stuff off the diagram to keep it simple.

 

[Filbert]

Another question - anyone ever use a EPDM pond liner to make a reseroir?

 

[OldMedUser]

"So here's my questions -

How long can the plant roots in the grow chamber be exposed to air without getting damaged?
There will always be about 2 inches of nutrient solution even when changing nutes, and the bubbler will remain on. I'm expecting a nute change to take about 30-45 minutes."

No problem. As long as the rez has the lid on to hold the humidity and keep light out you can take a couple of hours at least. I do mine in Rubber Maid tubs. When I want to do a nute change I premix in a fresh tub then lift the lid with the pots, roots and all and drop them on the new mix. Plug in the air stone and I'm good to go.

"Can I replenish the 75% of the system fluids with non-nute pH balanced water, and then add the remaining 25% fluids WITH nutes to the reservoir for circulation/mixing without shocking the plants?"

Another no problem, tho you'd be better off if the nutes are mixed/balanced b4 filling rez. Less chance of screw-ups.

Later .... |:^{)

LabRat

 

[Filbert]

Thanks LabRat, I like the idea of premixing the entire batch. Just gotta figure out where to put the drum. Think I'm gonna build a low profile res with some pond liner. If it works, I'll let ya know.